REPAIRING / SERVICING TV BBK 40LEM-1058

Technical description and composition of the BBK 40LEM-1058 TV, panel type and modules used. The composition of the modules.

BBK LED
Model: 40LEM-1058 / FT2C

Chassis / Version: CV512-U42

Panel: V400HJ6-PE1

LED driver (backlight): integrated into MainBoard

PWM LED driver: OB3352CP

MOSFET LED driver: TO-252 MDD1051

Power Supply (PSU): integrated into MainBoard

PWM Power: PWM SOT23-6

MOSFET Power: 65R280Q

MainBoard: CV512-U42

IC MainBoard: SPI Flash: 25Q64

Tuner: RDA5160

Specifications 40LEM-1058 / FT2C
BBK 40LEM-1058
General recommendations for TV LCD LED repair
Possible malfunctions

- TV BBK 40LEM-1058 does not turn on at all. There is no reaction to the remote control and control buttons from the front panel. Indicator lamps do not light up or flash.

A malfunction in such cases should be looked for primarily in the circuit of a switching power supply (SMPS) - a converter (AC / DC) of the mains voltage, which is combined with the MainBoard CV512-U42 in this model. It is then necessary to measure its output voltages and, if they are absent, the power switches (65R280Q) and rectifier diodes of the converters should be checked for the probability of a short circuit.
In the event of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor in the source of the key usually breaks off.
The breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM regulators (PWM) PWM SOT23-6, if they do not have visible damage to the case and an open short circuit between the pins, are usually checked by replacing.

- There is no image, the screen is black, there is sound, when the screen is illuminated outside, you can sometimes see barely noticeable outlines of the image.

In such cases, the most likely malfunction of the LED panel backlighting elements. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
When trying to detect a break in the LED lines, it should be borne in mind that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

- The TV does not turn on, the indicator signals the standby or operating mode, or blinks.

Repair or diagnostics of the CV512-U42 motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Checking or replacing SPI Flash: 25Q64 requires the necessary training and professional skills to repair modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by the warm-up method.

Before changing the tuner RDA5160, if there is no possibility of tuning to television channels, you should make sure that there are supply voltages, which must be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange between the tuner and the processor can be monitored with an oscilloscope

Owners of the 40LEM-1058 TV are advised to contact only qualified specialists with the necessary work experience for repair! Attempts to repair yourself without the appropriate knowledge and skills can lead to irreversible negative consequences!

Revision after repair of the backlight. Information from the master.

Decrease the backlight current from 260 mA to 125 mA - removed two measuring resistors from four connected in parallel in the current sensor.

Additional MainBoard Repair

The appearance of the MainBoard CV512-U42 is shown in the figure below:

CV512-U42

Main features of the BBK 40LEM-1058 device:

Installed matrix (LED panel) V400HJ6-PE1.
To power the backlight LEDs, a converter combined with the CV512-U42 main board is used, controlled by the OB3352CP PWM controller. TO-252 MDD1051 switches are used as power elements of the LED driver.
The power module is combined with the MainBoard and is made according to the AC / DC flyback voltage converter using SOT23-6 PWM microcircuits and 65R280Q power switches. 

 

PWM SMPS in SOT-23-6, SOT-26, TSOP-6 packages

In the circuitry of modern switching power supplies (SMPS), PWM controllers made in small-sized planar packages with six terminals have gained wide popularity. The enclosure type designation can be SOT-23-6, SOT-23-6L, SOT-26, TSOP-6, SSOT-6. The appearance and arrangement of the pins are shown in the figure below. In this case, the code marking LD7530A is shown on the left fragment of the picture.


 

 Pin assignment:
1 - GND. (Common wire).
2 - FB. (FeedBack - Feedback). Input for controlling the duration of pulses with a signal from the output voltage. Sometimes it can be labeled COMP (input comparator).
3 - RI / RT / CT / COMP / NC - Depending on the type of microcircuit, it can be used for a frequency-setting RC circuit (RI / RT / CT), or for organizing protection, as an input of a PWM trip comparator at a threshold value at its input, specified in the document. In some types of microcircuits, this input may not be used in any way (NC - No Connect).
4 - SENSE, otherwise CS (Current Sense) - Input from the current sensor at the source of the key.
5 - VCC - Input voltage supply and start of the microcircuit.
6 - OUT (GATE) - Output for controlling the gate (Gate) of the key.

Functionally, these regulators work on the principle of the previously popular xx384x PWM microcircuits, which have proven themselves well in terms of reliability and stability.

Some difficulties often arise when replacing or choosing an analog for such PWM regulators due to the use of code markings in the designation of the type of microcircuits. The situation is complicated by a large number of component manufacturers who do not always provide documentation to the mass access, just as not all manufacturers of finished devices supply repair service centers with diagrams, so repairmen often have to study real circuit solutions by installed components and wiring connections directly on the board.

In practice, PWM microcircuits and the marking code EAxxx and Eaxxx are often found. Official documentation for them was not found in the public domain, but discussions on the forums and pieces of pictures from PDF from System General, which publishes them as SG6848T and SG6848T2, have survived. The drawing is here placed left .


 

For the attention of the masters, here below are PDF datasheet tables compiled from information available on the Internet and PDF documents for the selection of analogues types when replacing the most common six-legged planar PWM with pinout pins: pin1 - GND, pin2 - FB (COMP), pin4 - Sense, pin5 - Vcc, pin6 - OUT ...
Their main difference is the application and purpose of pin 3. 

 

Name	Part Number	Fabricant	Marking
SG6849	SG684965TZ	Fairchild / ON Semi	BBxx
SG6849	SG6849-65T, SG6849-65TZ	System General	MBxx EBxx
SGP400	SGP400TZ	System General	AAKxx

 

 PWM controllers (PWM) with a 95-100 kOhm resistor on pin 3.

When applying the PWM listed below, the frequency should be set with the RT (RI) resistor from pin 3 to ground. Usually its nominal value is chosen 95-100 kOhm for a frequency of 65-100 KHz. For more details, see the here below attached documentation. PDF files are packed in RAR.

 

Name	Part Number	Fabricant	Marking
AP3103A	AP3103AKTR-G1	Diodes Incorporated	GHL
AP8263	AP8263E6R, A8263E6VR	AiT Semiconductor	S1xx
AT3263	AT3263S6	ATC Technology	3263
CR6848	CR6848S	Chip-Rail	848H16
CR6850	CR6850S	Chip-Rail	850xx
CR6851	CR6851S	Chip-Rail	851xx
FAN6602R	FAN6602RM6X	Fairchild / ON Semi	ACCxx
FS6830	FS6830	FirstSemi
GR8830	GR8830CG	Grenergy	30xx
GR8836	GR8836C, GR8836CG	Grenergy	36xx
H6849	H6849NF	HI-SINCERITY
H6850	H6850NF	HI-SINCERITY
HT2263	HT2263MP	HOT-CHIP	63xxx
KP201		Kiwi Instruments
LD5530	LD5530GL LD5530R	Leadtrand	xxt30 xxt30R
LD7531	LD7531GL, LD7531PL	Leadtrend	xxP31
LD7531A	LD7531AGL	Leadtrend	xxP31A
LD7535/A	LD7535BL, LD7535GL, LD7535ABL, LD7535AGL	Leadtrend	xxP35-xxx35A
LD7550	LD7550BL, LD7550IL	Leadtrend	xxP50
LD7550B	LD7550BBL, LD7550BIL	Leadtrend	xxP50B
LD7551	LD7551BL/IL	Leadtrend	xxP51
LD7551C	LD7551CGL	Leadtrend	xxP51C
NX1049	XN1049TP	Xian-Innuovo	49xxx
OB2262	OB2262MP	On-Bright-Electronics	62xx
OB2263	OB2263MP	On-Bright-Electronics	63xx
PT4201	PT4201E23F	Powtech	4201
R7731	R7731GE/PE	Richtek	0Q=
R7731A	R7731AGE	Richtek	IDP=xx
SD4870	SD4870TR	Silan Microelectronics	4870
SF1530	SF1530LGT	SiFirst	30xxx
SG5701	SG5701TZ	System General	AAExx
SG6848	SG6848T, SG6848T1, SG6848TZ1, SG6848T2	Fairchild / ON Semi	AAHxx EAxxx
SG6858	SG6858TZ	Fairchild / ON Semi	AAIxx
SG6859A	SG6859ATZ, SG6859ATY	Fairchild / ON Semi	AAJFxx
SG6859	SG6859TZ	Fairchild / ON Semi	AAJMxx
SG6860	SG6860TY	Fairchild	AAQxx
SP6850	SP6850S26RG	Sporton Lab	850xx
SP6853	SP6853S26RGB, SP6853S26RG	Sporton Lab	853xx
SW2263	SW2263MP	SamWin
UC3863/G	UC3863G-AG6-R	Unisonic Technologies Co	U863 U863G
XN1049	XN1049, XN1049TP	Innuovo Microelectronics	49 xxx

 

 PWM controllers that use pin 3 differently.

When using the following PWM (PWM controllers), you should pay attention to pin 3, which can be used to organize protection - thermal or from overvoltage of the input voltage.
The frequency can be fixed at 65kHz, or set by the value of the capacitor at pin 3.
When replacing any microcircuits with analogs, carefully study the documentation. PDF files are packed in a RAR archive.

 

Name	Part Number	Fabricant	Marking
AP3105/V/L/R	AP3105KTR-G1, AP3105VKTR-G1, AP3105LKTR-G1, AP3105RKTR-G1	Diodes Incorporated	GHN GHO GHP GHQ
AP3105NA/NV/NL/NR	AP3105NAKTR-G1, AP3105NVKTR-G1, AP3105NLKTR-G1, AP3105NRKTR-G1	Diodes Incorporated	GKN GKO GKP GKQ
AP3125A/V/L/R	AP3125AKTR-G1, AP3125VKTR-G1, AP3125LKTR-G1, AP3125RKTR-G1	Diodes Incorporated	GLS GLU GNB GNC
AP3125B	AP3125BKTR-G1	Diodes Incorporated	GLV
AP3125HA/HB	AP3125HAKTR-G1, AP3125HBKTR-G1	Diodes Incorporated	GNP GNQ
AP31261	AP31261KTR-G1	Diodes Incorporated	GPE
AP3127/H	AP3127KTR-G1, AP3127HKTR-G1	Diodes Incorporated	GPH GSH
AP3301	AP3301K6TR-G1	Diodes Incorporated	GTC
FAN6862	FAN6862TY	Fairchild / ON Semi	ABDxx
FAN6863	FAN6863TY, FAN6863LTY, FAN6863RTY	Fairchild / ON Semi	ABRxx
HT2273	HT2273TP	HOT-CHIP	73xxx
LD7510/J	LD7510GL, LD7510JGL	Leadtrend	xxP10 xxP10J
LD7530/A	LD7530PL, LD7530GL, LD7530APL, LD7530AGL	Leadtrend	xxP30 xxxP30A
LD7532	LD7532GL	Leadtrend	xxP32
LD7532A	LD7532AGL	Leadtrend	xxP32A
LD7532H	LD7532HGL	Leadtrend	xxP32H
LD7533	LD7533GL	Leadtrend	xxP33
LD7536	LD7536GL	Leadtrend	xxP36
LD7536R	LD7536RGL	Leadtrend	xxP36R
LD7537R	LD7537RGL	Leadtrend	xxP37R
LD7539C GL	LD7539C GL	Leadtrend	xxP39C
ME8204	ME8204M6G	MicrOne	ME8204xx
NCP1250	NCP1250ASN65T1G, NCP1250BSN65T1G, NCP1250ASN100T1G, NCP1250BSN100T1G	ON Semiconductor	25xxxx
NCP1251	NCP1251ASN65T1G, NCP1251BSN65T1G, NCP1251ASN100T1G, NCP1251BSN100T1G	ON Semiconductor	5xxxxx
OB2273	OB2273MP	On-Bright-Electronics	73xx
R7735	R7735AGE, R7735HGE, R7735GGE, R7735RGE, R7735LGE	Richtek
UC3873/G	UC3873-AG6-R, UC3873G-AG6-R	Unisonic Technologies	U873 U873G

 

LED TV BBK 40LEM-1058 / FT2C with LCD V400HJ6-PE1, diagonal size 39.5 "(100 cm) 16: 9. The required brightness of the screen of 250 cd / m2 is provided by LED backlighting. The ratio of maximum brightness to minimum ( contrast) is 3000: 1. The display technology of the model is implemented with LED backlighting.
The V400HJ6-PE1 sensor and MainBoard CV512-U42 software realize high quality HD images at a resolution of 1920x1080 pixels in 1080p (Full HD) graphics. Supported media file formats: MP3, HEVC (H.265), MKV, JPEG.
Speaker power 16 W (2x8 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, VGA, HDMI x3, USB x2. A headphone output is provided. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C standards.

A power supply unit is used as part of the MainBoard.

Dimensions: with stand 919x583x193 mm, without stand 919x536x76 mm.

TV weight: 5.8 kg.

Attention! The V400HJ6-PE1 panel of the BBK 40LEM-1058 / FT2C LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it flows down the glass onto the cables to make the TV unrepairable.

REPAIRING / SERVICING TV BBK 42LEX-5027

Technical description and composition of the BBK 42LEX-5027 TV, panel type and modules used. The composition of the modules.

BBK LED
Model: 42LEX-5027 / FT2C

Chassis / Version: CV338H-T42

Panel: CX420DDLEDM

LED backlight: CX42D10-ZC21FG-03

LED driver (backlight): integrated into MainBoard

PWM LED driver: BIT3267

MOSFET LED driver: AOD4454

Power Supply (PSU): integrated into MainBoard

PWM Power: PWM SOT23-6

MOSFET Power: 7R600

MainBoard: CV338H-T42

IC MainBoard: CPU: MSD6A338, SPI Flash: W25Q16DVSSIG, Audio: VA2221TSG28, EMMC: THGBM8G5D1KBAIL

Tuner: CDT-9NT372-RF01

Specifications 42LEX-5027 / FT2C
BBK 42LEX-5027
General recommendations for TV LCD LED repair
Possible manifestations of defects

- BBK 42LEX-5027 does not turn on and does not show any signs of operability at all. Does not blink indicators and does not respond to control buttons.

A malfunction in such cases should be looked for in the elements of the power source - the mains voltage converter (AC / DC), which is located on the main board MainBoard CV338H-T42. It is necessary to make sure that its output voltages are present and, if they are completely absent, check the power switches (7R600) and rectifier diodes for a possible short circuit.
In case of breakdowns in the secondary circuits of the converter, it can usually work in an emergency mode in a short circuit mode, and with a short circuit in the power elements of the primary circuit, the mains fuse or current sensor in the source of the key is most often cut off.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can disable it in key mode, or provoke an excess of the maximum current or voltage values. These can be circuits supplying a PWM controller, damper or frequency setting circuits, or OOS (negative feedback) elements in the stabilization circuit. PWM controllers (PWM) PWM SOT23-6, in the absence of external damage and a short circuit between the terminals, are checked by replacing them with a known good one.

If the BBK 42LEX-5027 / FT2C has no picture, but there is sound, often the CX420DDLEDM display backlight simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.

Replacing the LEDs requires disassembling the CX420DDLEDM LCD panel, a process that requires experience and qualifications from the technician. We do not recommend doing such work on your own to the owners of TVs and craftsmen who do not have experience in repairing LCD panels

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light can be seen through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But the main board MainBoard CV338H-T42 often turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, the fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within the normal range, it is necessary to use an oscilloscope to trace the passage of LVDS signals from the MainBoard CV338H-T42, as well as synchronization signals to the loops with drivers.

Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

- There is no picture, but there is sound and reaction to commands from the remote control. Or the image appears immediately after switching on and disappears.

The backlight of the matrix (LED panel) is usually faulty in these cases. Often the reason is a malfunction of the LEDs (open, short ...), or connectors of the straps (strings) CX42D10-ZC21FG-03, less often the LED driver is faulty.
It should be remembered that it is not possible to determine an open circuit in the LED lines without disassembling the panels using a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required. Then you need to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow opening the LED in the forward direction or dual LEds are used, then the PN transition of the emergency zener diode can indirectly serve as an indicator of serviceability. In the event of a malfunction of the LED-a, the PN-junction of the Zener diode will either be cut off or broken through in the SC.

- The TV does not go into operation, does not respond to the remote control. The indicator on the front panel is on or blinking.

Repair or diagnostics of the CV338H-T42 motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). When repairing an MB board, you need to check its components CPU: MSD6A338, SPI Flash: W25Q16DVSSIG, Audio: VA2221TSG28, EMMC: THGBM8G5D1KBAIL. Defective elements must be replaced. If chips with BGA soldering technology are used, the problem in its implementation is detected by local heating of the chip.

Before changing the CDT-9NT372-RF01 tuner, if it is not possible to tune to TV channels, you should make sure that there are supply voltages, which must be measured at the corresponding tuner terminals and check the software for correctness. The pulses of data exchange between the tuner and the processor can be monitored with an oscilloscope

Attention! Users and owners of 42LEX-5027 TVs who do not have the appropriate qualifications, knowledge and experience are strongly discouraged from attempting to repair themselves in order to avoid negative consequences that may lead to complete non-repairability of the device.


DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>   BBK 32LEX-5024 Chassis CV338H-T42-13B.


Revision after repair of the backlight. CV338H-T42. Information from the master.

Decrease the backlight current from 530 mA to 330 mA - removed two 1.5 Ohm resistors (PR182-PR183) from the current sensor. There are two 1.0 Ohm left.
Driver current limitation. CV338H-T42, BIT3267S. 

General information.

To reduce the backlight current in LED drivers with a BIT3267 controller, increase the total resistance of the low-resistance current sensor resistors Rset connected to INN pin 5 of the BIT3267 microcircuit.
The total resistance RLed can be calculated from the ratio RLed = 0.21 / ILed.
Sensor resistors PR182, PR183, PR203, PR238 are located next to the JW1 connector on the CV338H-T42 board. 

The pdf document is attached ------------> BIT3267.

 
Additional MainBoard Repair

The appearance of the MainBoard CV338H-T42 is shown in the figure below:

CV338H-T42

CV338H-T42 can be used in TVs:

BBK 32LEX-5023 / T2C (Panel V320BJ6-Q01 Rev. C1 (TH32YS1705C0327)), BBK 32LEX-5024 / T2C (Panel TH32YS1704D0089).

Main features of the BBK 42LEX-5027 device:

Installed matrix (LED-panel) CX420DDLEDM.
To power the backlight LEDs, a converter combined with the CV338H-T42 main board is used, controlled by the BIT3267 PWM controller. The keys of the AOD4454 type are used as power elements of the LED driver.
The power module is combined with the MainBoard and is made according to the AC / DC flyback voltage converter using PWM SOT23-6 microcircuits and power switches of the 7R600 type.
MainBoard - the main board (motherboard) is a CV338H-T42 module, using CPU chips: MSD6A338, SPI Flash: W25Q16DVSSIG, Audio: VA2221TSG28, EMMC: THGBM8G5D1KBAIL and others.
The CDT-9NT372-RF01 tuner provides reception of television programs and tuning to channels.

LED TV BBK 42LEX-5027 / FT2C with LCD CX420DDLEDM, diagonal 42 "(107 cm) in 16: 9 format. The required screen brightness of 250 cd / m² is provided by LED backlighting. The ratio of maximum brightness to minimum (contrast) is 4000: 1. The display technology of the model is implemented with LED backlighting.
The CX420DDLEDM sensor and MainBoard CV338H-T42 software realize high quality HD images at a resolution of 1920x1080 pixels in 1080p (Full HD) graphics.
42LEX-5027 / FT2C has built-in SMART software and pre-installed Android Operating System. Internet connection can be made via Wi-Fi wireless connection. Supported media file formats: MP3, WMA, MPEG4, MKV, JPEG.
Speaker power 16 W (2x8 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, component, VGA, HDMI x3, USB x3, Ethernet (RJ-45), Wi-Fi 802.11n, Miracast. A headphone output is provided. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C standards.

A power supply unit is used as part of the MainBoard.

Dimensions: With stand 952x598x220 mm, Without stand 952x556x92 mm.

TV weight: 8.4 kg.

Attention! The CX420DDLEDM panel of the BBK 42LEX-5027 / FT2C LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it flows down the glass onto the cables to make the TV unrepairable. 

REPAIRING / SERVICING TV BBK 43LEM-1018

Technical description and composition of the BBK 43LEM-1018 TV, panel type and modules used. The composition of the modules.

BBK LED
Model: 43LEM-1018 / FT2C

Chassis / Version: JUC7.820.00125910

Panel: C430F15-E1-A

LED driver (backlight): integrated into MainBoard

PWM LED driver: MP4012

MOSFET LED driver: AOD458 TO-252

Power Supply (PSU): R-HS105D-1MF11 XR7.820.497V1.5

PWM Power: NCP1271A, PFC: FA5591N

MainBoard: JUC7.820.00125910

IC MainBoard: 25Q64, TPS54428 IAGMF, RT9108NB

Tuner: CH DM121 C816RH

Specifications 43LEM-1018 / FT2C
BBK 43LEM-1018
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions

- TV BBK 43LEM-1018 does not turn on. There are no signs of operability. The indicators on the front panel do not light up or blink, the TV does not respond to the control buttons.

In such cases, the fault should be looked for first of all in the R-HS105D-1MF11 power module. Then you should measure its output voltages and, in case of their complete or partial absence, it is necessary to check the serviceability of the power switches and rectifier diodes of the converters for the presence of a possible short circuit.
In case of breakdowns in the secondary circuits, the converter, as a rule, can operate in an emergency mode in a short circuit mode, and in case of a short circuit in the power elements of the primary circuit, the mains fuse is usually cut off.
The breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM controllers (PWM) NCP1271A, PFC: FA5591N, if they do not have visible damage to the case and an outright short circuit between the pins, are usually checked by replacement.

- There is no picture, but there is sound, it reacts to the remote control. Or the image appears when turned on and immediately disappears

In such cases, the most likely malfunction of the LED panel backlighting elements. Most often, the reason for this is a break in the LEDs, or poor contact in the connectors of the brackets, less often the LED driver may be faulty.
To test the LED strips, to open all the transitions of the LEDs, you need several tens of volts or more, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED junctions in forward bias, you can sometimes detect the presence of a protective zener diode PN junction by connecting the probes in the opposite direction. If the zener diode is cut off or broken in the K / Z, then the LED is faulty and needs to be replaced.

If the BBK 43LEM-1018 / FT2C has no picture, but there is sound, the backlight of the C430F15-E1-A display often simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.

Replacing the LEDs requires disassembling the LCD panel C430F15-E1-A - a process that requires experience and qualifications from the technician. We do not recommend doing such work on your own to owners of TVs and craftsmen who do not have experience in repairing LCD panels.

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light is visible through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But often the main board MainBoard JUC7.820.00125910 also turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within normal limits, it is necessary to trace the passage of LVDS signals from MainBoard JUC7.820.00125910, as well as synchronizing signals to loops with drivers, with an oscilloscope.

Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.

- The TV does not go into operation, does not respond to the remote control. The indicator on the front panel is constantly on or blinking.

Repair or diagnostics of the JUC7.820.00125910 motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and the matrix. If necessary, you should update or replace the software (software). Sometimes it is necessary to check or replace (if necessary) elements of the MainBoard - 25Q64, TPS54428 IAGMF, RT9108NB. In cases where a BGA processor is used, its malfunction is usually detected by local warming up.

If there is no reception of television channels, but the TV is working properly from external devices, first of all, you need to check the supply voltage of the CH DM121 C816RH tuner and update the software. I2C communication pulses must be monitored with an oscilloscope.

I remind users again! Attempts to self-repair the BBK 43LEM-1018 TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!

Revision after repair of the backlight. Information from the master.

Decrease the backlight current from 400 mA to 300 mA - removed one of the 3.9 Ohm resistors (R421-R424) in the current sensor of the MP4012 driver on the XR7.820.497V1.5 board.
Additional MainBoard Repair

The appearance of the MainBoard JUC7.820.00125910 is shown in the figure below:

JUC7.820.00125910

JUC7.820.00125910 can be used in TVs:

DEXP F55B7200C (Panel C550F14-E6-L), DEXP F43B7200C (Panel C430F14-E1-L).

External view of the power supply

R-HS105D-1MF11:



Main features of the BBK 43LEM-1018 device:

Installed matrix (LED panel) C430F15-E1-A.
To power the backlight LEDs, a converter combined with the JUC7.820.00125910 main board is used, controlled by the MP4012 PWM controller. The keys of the AOD458 TO-252 type are used as power elements of the LED driver.


Technical description

LED TV BBK 43LEM-1018 / FT2C with LCD C430F15-E1-A, 43 "(109 cm) diagonal in 16: 9 format. The required screen brightness of 250 cd / m2 is provided by LED backlighting. The ratio of maximum brightness to minimum (contrast) is 3000: 1. This model uses edge LED side illumination.
The C430F15-E1-A sensor and the MainBoard JUC7.820.00125910 software realize high quality HD images at a resolution of 1920x1080 pixels in 1080p (Full HD) graphics. The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and formation of a digital signal occurs in the 480i, 480p, 576i, 576p, 720p, 1080i, 1080p standards. Supported media file formats: MP3, WMA, MPEG4, MKV, JPEG.
Speaker power of 6 W (2x3 W) is provided by two speakers. Uses the NICAM stereo signal processing system and the Sound Surround function.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, VGA, HDMI x3, USB, optical. A headphone output is provided. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector on the TV case is used; this interface supports resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C standards.

In'Ergo menu. Screen resolution: 1920x1080 Pix (Full HD). Diagonal (cm): 109. Diagonal (inch): 43.
Display:
Matrix backlight type: LED. Aspect ratio: 16: 9. Horizontal resolution (pix): 1920. Vertical resolution (pix): 1080. Horizontal viewing angle: 176. Vertical viewing angle: 176. Response time (ms): 6.5. Brightness (cd / m2): 250. Contrast: 3000: 1. Number of colors: 16,700,000.
Tuner:
DVB-T2. Ci + slot: 1. Analog TV tuner. DVB-T. DVB-C. Ci slot.
Analog tuner:
SECAM DK. Number of memorized channels: 100. Decoder NICAM stereo. Teletext.
Digital tuner:
Number of memorized channels: 1000. DVB-T MPEG4. Electronic program guide.
Sound parameters:
Number of built-in speakers (pcs): 2. Output power per channel (W): 8.
Inputs:
Composite (AV) (pcs): 1. Component Y Pb Pr video input (pcs): 1. SCART (pcs): 1. Antenna input RF In (pcs): 1. PC input VGA (D-SUB + PC Audio) ( pcs): 1. USB port (pcs): 1. HDMI (pcs): 3. HDMI version: 1.3.
Outputs:
Headphone output O 3.5 (pcs): 1. Coaxial digital audio output (pcs): 1.
USB version: 2.0. Noise suppression. Sleep timer. Menu languages: Russian, Ukrainian, English. VESA mount. VESA mount type: 200x200.
Remote control:
The presence of a remote control. Remote control battery: AAA. Number of batteries for the remote control (pcs): 2.
Power supply:
Power supply type: Built-in. On Mode Power Consumption (W): 85
Built-in PSU:
Input supply voltage (V (Hz)): 100-240 ~ 50/60.
Dimensions:
Width (mm): 965. Height (mm): 655. Depth (mm): 160. With stand: Width (mm): 965. Weight (kg): 8.6. Packing: Width (mm): 1065. Weight (gross) (kg): 11.05.
Appearance:
Body color: Black (B). Front panel trim: Plastic.
Completeness:
Additional remote control (mini). Remote control. Battery (pcs): 4. Mount for the stand. Manual. Warranty card.


The power supply unit XR7.820.497V1.5 is used.

Dimensions: With stand 965x619x209 mm, Without stand 965x562x77 mm.

TV weight: 8.5 kg.

Attention! Panel C430F15-E1-A LED TV BBK 43LEM-1018 / FT2C is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it flows down the glass onto the cables to make the TV unrepairable. 

REPAIRING / SERVICING TV BBK 43LEX-5056

Technical description and composition of the BBK 43LEX-5056 TV, panel type and modules used. The composition of the modules.

BBK LED
Model: 43LEX-5056 / FT2C

Chassis / Version: CV338H-T42

Panel: V400HJ6-PE1

LED backlight: 3 Strings x 8 Leds 3030 3V

LED driver (backlight): integrated into MainBoard

PWM LED driver: BIT3267

MOSFET LED driver: AOD4454

Power Supply (PSU): integrated into MainBoard

PWM Power: PWM SOT23-6

MOSFET Power: 70R380P

MainBoard: CV338H-T42

IC MainBoard: CPU: MSD6A338, MSB102KT, W25Q16DVSSIG, MP7752, VA2221TSG28 (audio), THGBM8G5D1KBAIL (EMMC FLASH)

Tuner: CDT-9NT372RF-10 (R842)

Specifications 43LEX-5056 / FT2C
BBK 43LEX-5056
General recommendations for TV LCD LED repair
Possible manifestations of defects

- BBK 43LEX-5056 does not turn on, does not respond to buttons and the remote control, indicators on the front panel do not light or flash.

In this case, first of all, you should check the operability of the main power source - the AC / DC voltage converter, all the elements of which are located on the MainBoard CV338H-T42. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches (70R380P) and rectifier diodes for possible partial or complete breakdown.
In the event of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor in the source of the key usually breaks off.
The breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM regulators (PWM) PWM SOT23-6, if they do not have visible damage to the case and an open short circuit between the pins, are usually checked by replacing.

- There is no image, there is sound, it reacts to the remote control. Or, immediately after switching on for a second, the image may appear and immediately disappear.

In some of these cases, the malfunction is caused by the lack of display backlighting. The reason may be found in the malfunction of the LEDs, in the violation of the contact connections of the LED strips 3 Strings x 8 Leds 3030 3V, or in the provision of their power supply (LED driver).
To test the LED strips, to open all the transitions of the LEDs, you need several tens of volts or more, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED junctions in forward bias, you can sometimes detect the presence of a protective zener diode PN junction by connecting the probes in the opposite direction. If the zener diode is cut off or broken in the K / Z, then the LED is faulty and needs to be replaced.

- The TV does not turn on, the indicator signals the standby or operating mode, or blinks.

Repair or diagnostics of the CV338H-T42 motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In cases of complex MB (SSB) repairs and with the necessary skills and equipment, it may sometimes be necessary to replace its CPU chips: MSD6A338, MSB102KT, W25Q16DVSSIG, MP7752, VA2221TSG28 (audio), THGBM8G5D1KBAIL (EMMC FLASH) and other possible faulty components. Malfunctions associated with the use of BGA soldering technologies are usually easily diagnosed by the warm-up method.

Before changing the tuner CDT-9NT372RF-10 (R842), if it is not possible to tune to TV channels, you should make sure that there are supply voltages, which must be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange between the tuner and the processor can be monitored with an oscilloscope

Owners and users of the BBK 43LEX-5056 TV should remember that self-repair without special knowledge, skills and qualifications may be fraught with negative consequences that can lead to complete non-repairability of the device!

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

Revision after repair of the backlight. Information from the master.

Decrease the backlight current from 510 mA to 360 mA - removed one of the 1.0 Ohm resistors in the backlight current sensor on the CV338H-T42 board. Initially, two 1.0 Ohm and two 1.5 Ohm are installed.
Driver current limitation. CV338H-T42, BIT3267S. General information.

To reduce the backlight current in LED drivers with a BIT3267 controller, increase the total resistance of the low-resistance current sensor resistors Rset connected to the INN pin 5 of the BIT3267 microcircuit.
The total resistance RLed can be calculated from the ratio RLed = 0.21 / ILed.
Sensor resistors PR182, PR183, PR203, PR238 are located next to the JW1 connector on the CV338H-T42 board. The pdf document is attached. ------------>  BIT3267.

The appearance of the MainBoard CV338H-T42 is shown in the figure below:

CV338H-T42

CV338H-T42 can be used in TVs:

BBK 32LEX-5023 / T2C (Panel V320BJ6-Q01 Rev. C1 (TH32YS1705C0327)), BBK 32LEX-5024 / T2C (Panel TH32YS1704D0089).

Main features of the BBK 43LEX-5056 device:

Installed matrix (LED panel) V400HJ6-PE1.
To power the backlight LEDs, a converter combined with the CV338H-T42 main board is used, controlled by the BIT3267 PWM controller. The keys of the AOD4454 type are used as power elements of the LED driver.
The power module is combined with the MainBoard and is made according to the AC / DC flyback converter circuit using PWM SOT23-6 microcircuits and power switches of the 70R380P type.
MainBoard - the main board (motherboard) is a CV338H-T42 module, using CPU chips: MSD6A338, MSB102KT, W25Q16DVSSIG, MP7752, VA2221TSG28 (audio), THGBM8G5D1KBAIL (EMMC FLASH) and others.
Tuner CDT-9NT372RF-10 (R842) provides reception of television programs and tuning to channels.

If the BBK 43LEX-5056 / FT2C has no picture, but there is sound, often the V400HJ6-PE1 display backlight simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.

Replacing the LEDs requires disassembling the V400HJ6-PE1 LCD panel, a process that requires experience and qualifications from the technician. We do not recommend doing such work on your own to the owners of TVs and craftsmen who do not have experience in repairing LCD panels

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.
 

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light can be seen through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But the main board MainBoard CV338H-T42 often turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, the fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within the normal range, it is necessary to use an oscilloscope to trace the passage of LVDS signals from the MainBoard CV338H-T42, as well as synchronization signals to the loops with drivers.

Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.

Additional technical information about the panel:
Brand: INNOLUX
Model: V400HJ6-PE1 Rev.C2
Type: a-Si TFT-LCD, CELL
Diagonal size: 40 inch
Resolution: 1920x1080, FHD
Display Mode: MVA, Normally Black, Transmissive
Active Area: 878.112x485.352 mm
Surface: Antiglare (Haze 1%)
Glass Depth: 0.50 + 0.50 mm
Transmissivity: 6.0% (with Polarizer)
Contrast Ratio: 5000: 1
Display Colors: 16.7M (8-bit)
Response Time: 8.5 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V


LED TV BBK 43LEX-5056 / FT2C with LCD V400HJ6-PE1, diagonal size 43 "(109 cm) 16: 9. The required brightness of the screen of 250 cd / m2 is provided by LED backlighting. The ratio of maximum brightness to minimum ( contrast) is 1200: 1. The display technology of the model is implemented with LED backlighting.
The V400HJ6-PE1 sensor and MainBoard CV338H-T42 software realize high quality HD images at a resolution of 1920x1080 pixels in 1080p (Full HD) graphics.
The 43LEX-5056 / FT2C has built-in SMART software and pre-installed Android operating system. Internet connection can be made via Wi-Fi wireless connection. Supported media file formats: MP3, MPEG4, HEVC (H.265), MKV, JPEG.
Speaker power 16 W (2x8 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV x2, component, VGA, HDMI x3, USB x2, Ethernet (RJ-45), Wi-Fi 802.11n. A headphone output is provided. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C standards.

A power supply unit is used as part of the MainBoard.

Dimensions: with stand 971x611x212 mm, without stand 971x566x88 mm.

TV weight: 8.8 kg.

Attention! The V400HJ6-PE1 panel of the BBK 43LEX-5056 / FT2C LED TV is an expensive and unreliable element.
Do not allow any impacts on the glass and pressure on the surface of the screen to avoid damage to the LED-panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it flows down the glass onto the cables to make the TV unrepairable.

 

REPAIRING / SERVICING TV BBK 55LEX-6027

Technical description and composition of the BBK 55LEX-6027 TV, panel type and modules used. The composition of the modules.

BBK LED
Model: 55LEX-6027 / UTS2C

Chassis / Version: CV538H-A

Panel: LSC550FN22-W

LED driver (backlight): integrated into PSU

PWM LED driver: UCC25710

Power Supply (PSU): RS146S-4T03

PWM Power: PFC, PWM

MainBoard: CV538H-A

IC MainBoard: CPU: MSD6586PYE-8-SW, EMMC: KLM8G1GEME

Tuner: DVB-T2 & SAT

55LEX-6027 / UTS2C Specifications
BBK 55LEX-6027
General recommendations for TV LCD LED repair
Possible manifestations of defects

- TV BBK 55LEX-6027 does not turn on, does not respond to the remote control and control panel buttons, does not light or blink indicators.

Most often, with similar manifestations, the main power module RS146S-4T03 turns out to be faulty. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches and rectifier diodes for possible partial or complete breakdown.
In case of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and with a short circuit in the power elements of the primary circuit, the mains fuse and / or the current sensor in the source of the key usually breaks off.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can disable it in key mode, or provoke an excess of the maximum current or voltage values. These can be circuits supplying a PWM controller, damper or frequency setting circuits, or OOS (negative feedback) elements in the stabilization circuit. PWM controllers (PWM) PFC, PWM, in the absence of external damage and short circuit between the terminals, are checked by replacing them with known good ones.

- There is no picture, but there is sound and all other TV functions are working. The image sometimes appears for a second immediately after switching on and disappears.

The backlight of the matrix (LED panel) is usually faulty in these cases. Usually the cause of the malfunction is in the breakage of the LEDs, or in the connectors of the LED strips, but sometimes the LED driver is also faulty.
When diagnosing, it must be borne in mind that it is impossible to check for an open in the circuit of the LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally a current source. Opening the panel, you can check each LED separately. Typically, Chinese multimeters will lightly light one 3-volt LED when the probes are connected to it in the forward direction. For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of the LED health. In the event of a malfunction of the LED, its zener diode will either be cut off or pierced in the K / Z.

If the BBK 55LEX-6027 / UTS2C has no picture, but there is sound, often the LSC550FN22-W display backlight simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.

Replacing the LEDs requires disassembling the LCD panel LSC550FN22-W - a process that requires experience and qualifications from the master. We do not recommend doing such work on your own to owners of TVs and craftsmen who do not have experience in repairing LCD panels

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light is visible through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But the main board MainBoard CV538H-A often turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within normal limits, it is necessary to trace the passage of LVDS signals from the MainBoard CV538H-A with an oscilloscope, as well as synchronizing signals to the loops with drivers.

Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

 
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals the standby mode.

Repair or diagnostics of the CV538H-A motherboard should begin with checking the stabilizers and power converters required to power the microcircuits and matrix. If necessary, you should update or replace the software (software). When repairing an MB board, it is necessary to check its components CPU: MSD6586PYE-8-SW, EMMC: KLM8G1GEME. Defective elements must be replaced. If chips with BGA soldering technology are used, the problem in its implementation is detected by local heating of the chip.

If there is no reception of TV channels, but the TV is working properly from external devices, first of all, you need to check the supply voltage of the DVB-T2 & SAT tuner and update the software. I2C communication pulses must be monitored with an oscilloscope.

Users and owners of TVs should remember that attempts to self-repair the BBK 55LEX-6027 TV without the appropriate qualifications and the necessary experience can lead to serious negative consequences!

Revision after repair of the backlight. RS146S-4T03. Information from the master.

Current sensor - four resistors 2.9 Ohm 2W and six planar 10 Ohm 0.5W.
Decrease the backlight current from 500 mA to 250 mA - removed two large 2.9 Ohm resistors and two planar 10 Ohm resistors from the back side of the RS146S-4T03 board in the current sensor.
Additional MainBoard Repair

The MainBoard CV538H-A is shown in the figure below:

CV538H-A

External view of the power supply

RS146S-4T03:

RS146S-4T03

Main features of the BBK 55LEX-6027 device:

Installed matrix (LED panel) LSC550FN22-W.
To power the backlight LEDs, a converter combined with a power supply is used, controlled by the UCC25710 PWM controller.

The formation of the necessary supply voltages for all nodes of the BBK 55LEX-6027 TV is carried out by the RS146S-4T03 power module, or its analogs using PFC, PWM microcircuits.
MainBoard - the main board (motherboard) is a CV538H-A module, using CPU chips: MSD6586PYE-8-SW, EMMC: KLM8G1GEME and others.
The DVB-T2 & SAT tuner provides reception of television programs and tuning to channels.


LED TV BBK 55LEX-6027 / UTS2C with LCD LSC550FN22-W, diagonal size 54.6 "(139 cm) 16: 9 format. The required screen brightness of 250 cd / m2 is provided by LED backlighting. The ratio of maximum to minimum brightness ( contrast) is 4500: 1. The display technology of the model is implemented with LED backlighting.
LSC550FN22-W sensor and MainBoard CV538H-A software realize high-quality UHD images at 3840x2160 pixels in 4K UHD, HDR standard. Image processing is implemented using modern High Dynamic Range (HDR) technology with an extended range of brightness gradations.
55LEX-6027 / UTS2C has built-in SMART software and pre-installed Android operating system. Internet connection can be made via Wi-Fi wireless connection. Supported media file formats: MP3, WMA, MPEG4, HEVC (H.265), MKV, JPEG.
Speaker power 16 W (2x8 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV x2, audio x2, component, VGA, HDMI x3, USB x2, Ethernet (RJ-45), Wi-Fi 802.11n. A headphone output is provided. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.

The power supply unit RS146S-4T03 is used.

Dimensions: with stand 1244x782x254 mm, without stand 1244x723x97 mm.

TV weight: with stand: 13.3 kg, without stand: 12.8 kg.

Attention! The LSC550FN22-W panel of the BBK 55LEX-6027 / UTS2C LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it flows down the glass onto the cables to make the TV unrepairable. 

REPAIRING / SERVICING TV SAMSUNG UE55MU6300U

Technical description and composition of the SAMSUNG UE55MU6300U TV, panel type and modules used. The composition of the modules.

SAMSUNG LED
Model: UE55MU6300U

Chassis / Version: AA01

Panel: CY-WM055HGAV1V

LED backlight: LM41-00135A, LM41-00136A

LED driver (backlight): integrated into PSU

PWM LED driver: SLC3011N

MOSFET LED driver: TO-220F

Power Supply (PSU): BN44-00807A L55S6_FHS

PWM Power: SPC7011F, FA6A20

MOSFET Power: N-FET TO-220F

MainBoard: BN41-02568B BN94-12426F

IC MainBoard: SDP1601, KLM4G1FEPD, 25Q40CLSIP, 25Q80DVSIG, TAS5749M

Tuner: BN40-00331A

Control: IR: KU6000 BN41-02324C, Wi-Fi: WCM730Q BN59-01264A

UE55MU6300U Specifications
SAMSUNG UE55MU6300U
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions

- TV SAMSUNG UE55MU6300U does not turn on and does not show any signs of operability at all. No response to the remote control and front panel control buttons.

A fault in such cases should be started to look for in the circuits of the BN44-00807A power supply. It is necessary to measure its secondary output voltages, and if they are absent, check the power switches (N-FET TO-220F) and rectifier diodes in the converters for a short circuit.
In case of any breakdowns in the secondary circuits, the converter can operate in an emergency mode of a short circuit, and with a short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key is often cut off.
Breakdown of Mos-Fet switches used in switching power supplies is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM regulator, in frequency-setting or damper circuits, as well as in negative feedback stabilization. PWM microcircuits (PWM) SPC7011F, FA6A20 are usually checked by replacing them with new ones, or known to be working properly.

- There is no picture, but there is sound, it reacts to the remote control. Or the image appears when turned on and disappears immediately

As a rule, in this case, the backlight of the LED panel is faulty. Usually, the cause of the malfunction is in the breakage of the LEDs, or in the connectors of the LED strips LM41-00135A, LM41-00136A, but sometimes the LED driver is also faulty.
It is impossible to check the line of series-connected LEDs without a special current source, and it is unsafe for them to use any voltage sources above 12V for this purpose. Then all that remains is to open the panel and check each LED separately. Usually, Chinese multimeters with 9V power supply lightly light up one 3-volt LED, if you connect the probes to it in the forward direction, the red probe to the anode, and the black one to the cathode. For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of the LED health. In the event of a malfunction of the LED, its zener diode will either be cut off or pierced in the K / Z.

If SAMSUNG UE55MU6300U has no picture, but there is sound, often the display backlight CY-WK055HGLV1V simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.

Replacing the LEDs requires disassembling the LCD panel CY-WK055HGLV1V - a process that requires experience and qualifications from the master. We do not recommend doing such work on your own to owners of TVs and craftsmen who do not have experience in repairing LCD panels.

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light is visible through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But the main board MainBoard BN41-02568B often turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within the normal range, it is necessary to use an oscilloscope to trace the passage of LVDS signals from the MainBoard BN41-02568B, as well as synchronization signals to the loops with drivers.

Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.

- The indicator blinks or is on constantly, the TV does not turn on, does not respond to the remote control.

Repair or diagnostics of the BN41-02568B motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - SDP1601, KLM4G1FEPD, 25Q40CLSIP, 25Q80DVSIG, TAS5749M with new or known good ones. In cases where BGA technologies are used, defects are usually localized by heating.

In cases where there is no tuning to terrestrial or cable TV channels, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltages at the terminals of the BN40-00331A tuner. It is also necessary to check with an oscilloscope the presence of pulses of data exchange between the tuner and the processor via the I2C bus.

Attention to users! Self-repair of the SAMSUNG UE55MU6300U TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!

Additional MainBoard Repair

The appearance of the MainBoard BN41-02568B is shown in the figure below:

BN41-02568B

External view of the power supply

BN44-00807A:



Main features of the SAMSUNG UE55MU6300U device:

Installed matrix (LED panel) CY-WM055HGAV1V.
A converter combined with a power supply is used to power the backlight LEDs and is controlled by the SLC3011N PWM controller. TO-220F switches are used as power elements of the LED driver.

The formation of the necessary supply voltages for all nodes of the SAMSUNG UE55MU6300U TV is carried out by the BN44-00807A power module, or its analogs using SPC7011F, FA6A20 microcircuits and N-FET TO-220F power switches.
MainBoard - the main board (motherboard) is a BN41-02568B module, using SDP1601, KLM4G1FEPD, 25Q40CLSIP, 25Q80DVSIG, TAS5749M and others.
The BN40-00331A tuner provides reception of television programs and tuning to channels.

Instructions and updates

There are files to download for the UE55MU6300UXCE  model from the manufacturer:

Latest software updates, firmware (latest firmwares):
File type File name Version Date Size
Update file (USB) T-KTMDEUC.zip 1280.5 11/14/2019 1281.95 Mb
Manual update 2017_TV_Firmware_Upgrade_Instruction_1.0_T-KTMDEUC.pdf 1.0 28.11.2018 0.28 Mb
Update file (USB) T-KTMDEUC_1280.5.exe 1280.5 11/14/2019 1281.65 Mb
Update file (USB) T-KTMDEUC_1280.5_RU.exe 1280.5 14.11.2019 1281.65 Mb

User Manuals and Instructions:
File type File name Version Date Size
User manual UMU6300P_EN_BN68-08445G-01_L04_170329.1.pdf 01 08.08.2017 19.35 Mb
Installation Guide QSG_UMU6300P_CIS_BN68-08410Y-01_170719.0.pdf 01 08.08.2017 0.21 Mb
Instruction PDF ENG_KTMDVBEUL-3.0.7_180111.1.pdf 3.0.7 23.01.2018 13.11 Mb
Instruction PDF RUS_KTMDVBEUL-3.0.7_180111.1.pdf 3.0.7 23.01.2018 10.8 Mb

Files can be downloaded from the manufacturer's website for the UE55MU6300UXCE model.


TV SAMSUNG UE55MU6300U with LCD CY-WK055HGLV1V, 55 "(140 cm) 16: 9 format diagonally. This model uses a panel with edge LED backlighting - Edge LED.
CY-WK055HGLV1V sensor and MainBoard BN41-02568B software are capable of realizing images in the highest UHD quality at 3840x2160 pixels in 4K UHD, HDR standard. Image processing is performed using modern High Dynamic Range (HDR) technology with an extended range of brightness gradations.
TV model UE55MU6300U has built-in SMART software and Tizen operating system installed. The connection to the network can be carried out via Wi-Fi wireless connection. The input analog video signal is decoded in PAL, SECAM, NTSC systems. Graphic processing of a digital signal is performed in the 480i, 480p, 576i, 576p, 720p, 1080i, 1080p standards. Supported media file formats: MP3, WMA, MPEG4, HEVC (H.265), DivX, MKV, JPEG.
Speaker power 20 W (2x10 W) is provided by two speakers. The NICAM stereo audio processing system and the Sound Surround function are used.
Communication with other devices via an external interface is supported by standard input and output connectors: antenna input (RF), AV, component, HDMI x3, USB x2, Ethernet (RJ-45), Bluetooth, Wi-Fi 802.11n, Miracast. A VGA (D-Sub 15) connector is provided to connect a computer or laptop to this TV model. This interface supports standard resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.

The power consumed when operating from the network is 210 W. Power supply BN44-00807A.

Dimensions: with stand 1242x779x311 mm, without stand 1242x719x112 mm.

TV weight: with stand: 17.9 kg, without stand: 16.7 kg.

Attention! Panel CY-WK055HGLV1V of SAMSUNG UE55MU6300U LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.

REPAIRING / SERVICING TV SAMSUNG UE55NU7100U

 Technical description and composition of the SAMSUNG UE55NU7100U TV, panel type and modules used. The composition of the modules.

SAMSUNG LED
Model: UE55NU7100U

Chassis / Version: KANT-M2E

Panel: CY-NN055HGLV2V

LED backlight: EDGE LED 55NU

LED driver (backlight): integrated into PSU

PWM LED driver: SLM4283A SOP-20 StepDown

MOSFET LED driver: N-FET TO-220F

Power Supply (PSU): BN44-00932B L55E6_NSM

PWM Power: PFC, PWM

MOSFET Power: N-FET TO-220F

MainBoard: BN41-02635B BN94-13275E

IC MainBoard: CPU, eMMC: KLM4G1FEPD, SPI 25Q40, EEPROM: 24C512, DRAM, AUDIO: TAS5749M

Tuner: BN40-00331A

UE55NU7100U Specifications
SAMSUNG UE55NU7100U
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions

- SAMSUNG UE55NU7100U TV does not turn on at all. No response to the remote control and front panel control buttons. Indicator lamps do not light up or flash.

Most likely in this case, the main switching power supply (SMPS) BN44-00932B is faulty. It is necessary to measure its output voltages, and in case of their absence (full or partial), the serviceability of the power switches (N-FET TO-220F) of the converters and rectifier diodes should be checked for a possible short circuit.
In case of any breakdowns in the secondary circuits, the converter can operate in an emergency mode of a short circuit, and with a short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key is often cut off.
Breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM controllers (PWM) PFC, PWM, if they do not have visible damage to the case and an outright short circuit between the pins, are usually checked by replacement.

- No picture, sound, all other TV functions are working. When turned on, the image may sometimes appear for a second.

The backlight of the matrix (LED panel) is usually faulty in these cases. The reason may be found in the malfunction of the LEDs, in the violation of the contact connections of the EDGE LED 55NU LED strips, or in the provision of their power supply (LED driver).
It is impossible to check the line of series-connected LEDs without a special current source, and it is unsafe for them to use any voltage sources above 12V for this purpose. Then all that remains is to open the panel and check each LED separately. Usually, Chinese multimeters with 9V power supply lightly light up one 3-volt LED, if you connect the probes to it in the forward direction, the red probe to the anode, and the black one to the cathode. For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of the LED health. In the event of a malfunction of the LED, its zener diode will either be cut off or pierced in the K / Z.

If SAMSUNG UE55NU7100U has no picture, but there is sound, often the display backlight CY-NN055HGLV2V simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.

Replacing the LEDs requires disassembling the LCD panel CY-NN055HGLV2V - a process that requires experience and qualifications from the master. We do not recommend doing such work on your own to the owners of TVs and craftsmen who do not have experience in repairing LCD panels

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV you can see light through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But often the main board MainBoard BN41-02635B turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within normal limits, it is necessary with an oscilloscope to track the passage of LVDS signals from the MainBoard BN41-02635B, as well as synchronization signals to the loops with drivers.

Flooded or unsuccessfully washed screens of LED-TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.

- The indicator on the front panel blinks, the TV does not turn on in operating mode, does not respond to the remote control.

Repair or diagnostics of the BN41-02635B motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In some cases, to repair the MB (SSB) board, it may be necessary to replace chips - CPU, eMMC: KLM4G1FEPD, SPI 25Q40, EEPROM: 24C512, DRAM, AUDIO: TAS5749M with new or known good ones. In cases where BGA technologies are used, defects are usually localized by heating.

If the TV operates normally from external devices, but does not tune to TV channels, the BN40-00331A tuner may be faulty. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the reason for the inoperability of the tuner may be a software failure.

Once again, we remind TV users: do not try to repair yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repairs to professionals with sufficient experience in the field of electronic repair.

Additional MainBoard Repair

The appearance of the MainBoard BN41-02635B is shown in the figure below:

BN41-02635B

External view of the power supply

Main features of the SAMSUNG UE55NU7100U device:

The matrix (LED-panel) CY-NN055HGLV2V is installed.
A converter combined with a power supply is used to power the backlight LEDs, and is controlled by the SLM4283A SOP-20 StepDown PWM controller. N-FET TO-220F switches are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the SAMSUNG UE55NU7100U TV is carried out by the BN44-00932B power module, or its analogs using PFC, PWM microcircuits and N-FET TO-220F power switches.

MainBoard - the main board (motherboard) is a BN41-02635B module, using CPU chips, eMMC: KLM4G1FEPD, SPI 25Q40, EEPROM: 24C512, DRAM, AUDIO: TAS5749M and others.
The BN40-00331A tuner provides reception of television programs and tuning to channels.

Instructions and updates

There are files to download for the UE55NU7100U  model from the manufacturer:

Latest firmware updates (latest firmwares):
File type File name Version Date Size
Update instruction 2018_TV_Firmware_Upgrade_Instruction_T-KTM2LDEUC.pdf 1.0 23.06.2020 0.5 Mb
Update file (USB) T-KTM2LDEUC.zip 1310.4 02.11.2020 1117.74 Mb
Update file (USB) T-KTM2LDEUC_1310.4.exe 1310.4 02.11.2020 1117.49 Mb
Update file (USB) T-KTM2LDEUC_1310.4_RU.exe 1310.4 02.11.2020 1117.49 Mb

User Manuals and Instructions:
File type File name Version Date Size
User manual BN68-08987G-02_UNU7100X_EN_L02_180710.1.pdf 02 13.07.2018 1.22 Mb
Brief instructions BN68-08995L-01_QSG_UNU7100X_CIS_180314.0.pdf 01 23.05.2018 0.3 Mb
Instruction PDF ENG_KM2DVBEUN-3.0.2_181205.0.pdf 3.0.2 02.01.2019 11.33 Mb
Instruction PDF RUS_KM2DVBEUN-3.0.2_181205.0.pdf 3.0.2 02.01.2019 11.42 Mb

Files can be downloaded from the manufacturer's website for the UE55NU7100  model.

 

 

SAMSUNG UE55NU7100U TV with LCD CY-NN055HGLV2V, diagonal 54.6 "(139 cm) in 16: 9 format. This model uses a panel with edge LED backlighting - Edge LED.
CY-NN055HGLV2V sensor and MainBoard BN41-02635B software are capable of realizing images in the highest UHD quality at 3840x2160 resolution in 4K UHD, HDR standard. Image processing is performed using modern High Dynamic Range (HDR) technology with an extended range of brightness gradations.
TV model UE55NU7100U has built-in software (software) SMART and installed Tizen Operating System. The connection to the network can be carried out via Wi-Fi wireless connection. Supported media file formats: MP3, WMA, MPEG4, HEVC (H.265), DivX, MKV, JPEG.
Speaker sound system power 20 W (2x10 W) is provided by two speakers. The NICAM stereo audio processing system and the Sound Surround function are used.
Communication with other devices via an external interface is supported by standard input and output connectors: antenna input (RF), AV, component, HDMI x3, USB x2, Ethernet (RJ-45), Wi-Fi 802.11ac, Miracast. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.

The power consumed when operating from the network is 150 W. BN44-00932B power supply.

Dimensions: with stand 1239x793x261 mm, without stand 1239x714x59 mm.

TV weight: with stand: 17.7 kg, without stand: 17.3 kg.

Attention! Panel CY-NN055HGLV2V LED TV SAMSUNG UE55NU7100U is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.

REPAIRING / SERVICING TV TCL L32S6300

Technical description and composition of the TCL L32S6300 TV, panel type and modules used. The composition of the modules.

TCL LED
Model: L32S6300

Chassis / Version: TPD.NT72563.PB771

Panel: LVW320ND1L

LED driver (backlight): integrated into MainBoard

PWM LED driver: GB98TERN

MOSFET LED driver: TO-252

Power Supply (PSU): integrated into MainBoard

PWM Power: PWM SOT23-6

MOSFET Power: TO-220

MainBoard: TPD.NT72563.PB771

IC MainBoard: EMMC THGBMDG5D1LBAIL

Tuner: NoName

L32S6300 Specifications
TCL L32S6300
General recommendations for TV LCD LED repair
Possible malfunctions

- TCL L32S6300 TV does not turn on. There are no signs of operability. The indicators on the front panel do not light or blink, the TV does not respond to control buttons.

In such cases, the AC / DC converter of the mains voltage, which is combined with the main board TPD.NT72563.PB771, is often faulty. It is then necessary to measure its output voltages and, if they are absent, the power switches (TO-220) and rectifier diodes of the converters should be checked for the probability of a short circuit.
In case of breakdowns in the secondary circuits, the converter, as a rule, can operate in an emergency mode in a short-circuit mode, and in case of a short circuit in the power elements of the primary circuit, the mains fuse is usually cut off.
Breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM controllers (PWM), if they do not have visible damage to the case and an outright short circuit between the terminals, are usually checked by replacing.

- There is no picture, but there is sound and reaction to the remote control. Or, for a second, the image may appear immediately after switching on.

The backlight of the matrix (LED panel) is usually faulty in these cases. Most often the reason for this is a break in the LEDs, or poor contact in the connectors of the brackets, less often the LED driver may be faulty.
To test the LED strips, in order to open all the transitions of the LEDs, several tens of volts or more are needed; it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED junctions in forward bias, you can sometimes detect the presence of a protective zener diode PN junction by connecting the probes in the opposite direction. If the zener diode is cut off or broken in K / Z, then the LED is faulty and needs to be replaced.

If TCL L32S6300 has no image, but there is sound, often the LVW320ND1L display backlight simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.

Replacing the LEDs requires disassembling the LVW320ND1L LCD panel - a process that requires experience and qualifications from the master. We do not recommend doing such work on your own to owners of TVs and craftsmen who do not have experience in repairing LCD panels

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light is visible through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But often the main board MainBoard TPD.NT72563.PB771 also turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within the normal range, it is necessary to trace the passage of LVDS signals from MainBoard TPD.NT72563.PB771 with an oscilloscope, as well as synchronizing signals to loops with drivers.

Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.

- The TV does not go into operation, does not respond to the remote control. The indicator on the front panel is on or blinking.

Repair or diagnostics of the TPD.NT72563.PB771 motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In cases of complex MB (SSB) repairs and with the necessary skills and equipment, it may sometimes be necessary to replace its EMMC THGBMDG5D1LBAIL chips and other possible faulty components. Malfunctions associated with the use of BGA soldering technologies are usually easily diagnosed by the warm-up method.

Attention to TV owners! Attempts to repair the TCL L32S6300 yourself are not recommended by the manufacturer and can lead to serious negative consequences!

 

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

 
Revision after repair of the backlight. Information from the master.

Reduce the backlight current from 92 mA to 66 mA - replaced one of the resistors (16 kOhm by 22 kOhm) at pin 6 ISET of the GB98TERN chip on the TPD.NT72563.PB771 board.
Additional MainBoard Repair

The appearance of the MainBoard TPD.NT72563.PB771 is shown in the figure below:

TPD.NT72563.PB771

Key features of the TCL L32S6300 device:

Installed matrix (LED panel) LVW320ND1L.
To power the backlight LEDs, a converter combined with the main board TPD.NT72563.PB771 is used, controlled by the GB98TERN PWM controller. TO-252 switches are used as power elements of the LED driver.
The power module is combined with the MainBoard and is made according to the AC / DC flyback voltage converter using SOT23-6 PWM microcircuits and TO-220 power switches. 

PWM SMPS in SOT-23-6, SOT-26, TSOP-6 packages

In the circuitry of modern switching power supplies (SMPS), PWM controllers made in small-sized planar packages with six terminals have gained wide popularity. The enclosure type designation can be SOT-23-6, SOT-23-6L, SOT-26, TSOP-6, SSOT-6. The appearance and arrangement of the pins are shown in the figure below. In this case, the code marking LD7530A is shown on the left fragment of the picture.


 

 Pin assignment:
1 - GND. (Common wire).
2 - FB. (FeedBack - Feedback). Input for controlling the duration of pulses with a signal from the output voltage. Sometimes it can be labeled COMP (input comparator).
3 - RI / RT / CT / COMP / NC - Depending on the type of microcircuit, it can be used for a frequency-setting RC circuit (RI / RT / CT), or for organizing protection, as an input of a PWM trip comparator at a threshold value at its input, specified in the document. In some types of microcircuits, this input may not be used in any way (NC - No Connect).
4 - SENSE, otherwise CS (Current Sense) - Input from the current sensor at the source of the key.
5 - VCC - Input voltage supply and start of the microcircuit.
6 - OUT (GATE) - Output for controlling the gate (Gate) of the key.

Functionally, these regulators work on the principle of the previously popular xx384x PWM microcircuits, which have proven themselves well in terms of reliability and stability.

Some difficulties often arise when replacing or choosing an analog for such PWM regulators due to the use of code markings in the designation of the type of microcircuits. The situation is complicated by a large number of component manufacturers who do not always provide documentation to the mass access, just as not all manufacturers of finished devices supply repair service centers with diagrams, so repairmen often have to study real circuit solutions by installed components and wiring connections directly on the board.

In practice, PWM microcircuits and the marking code EAxxx and Eaxxx are often found. Official documentation for them was not found in the public domain, but discussions on the forums and pieces of pictures from PDF from System General, which publishes them as SG6848T and SG6848T2, have survived. The drawing is here placed left .


 

For the attention of the masters, here below are PDF datasheet tables compiled from information available on the Internet and PDF documents for the selection of analogues types when replacing the most common six-legged planar PWM with pinout pins: pin1 - GND, pin2 - FB (COMP), pin4 - Sense, pin5 - Vcc, pin6 - OUT ...
Their main difference is the application and purpose of pin 3. 

 

Name	Part Number	Fabricant	Marking
SG6849	SG684965TZ	Fairchild / ON Semi	BBxx
SG6849	SG6849-65T, SG6849-65TZ	System General	MBxx EBxx
SGP400	SGP400TZ	System General	AAKxx

 

 PWM controllers (PWM) with a 95-100 kOhm resistor on pin 3.

When applying the PWM listed below, the frequency should be set with the RT (RI) resistor from pin 3 to ground. Usually its nominal value is chosen 95-100 kOhm for a frequency of 65-100 KHz. For more details, see the here below attached documentation. PDF files are packed in RAR.

 

Name	Part Number	Fabricant	Marking
AP3103A	AP3103AKTR-G1	Diodes Incorporated	GHL
AP8263	AP8263E6R, A8263E6VR	AiT Semiconductor	S1xx
AT3263	AT3263S6	ATC Technology	3263
CR6848	CR6848S	Chip-Rail	848H16
CR6850	CR6850S	Chip-Rail	850xx
CR6851	CR6851S	Chip-Rail	851xx
FAN6602R	FAN6602RM6X	Fairchild / ON Semi	ACCxx
FS6830	FS6830	FirstSemi
GR8830	GR8830CG	Grenergy	30xx
GR8836	GR8836C, GR8836CG	Grenergy	36xx
H6849	H6849NF	HI-SINCERITY
H6850	H6850NF	HI-SINCERITY
HT2263	HT2263MP	HOT-CHIP	63xxx
KP201		Kiwi Instruments
LD5530	LD5530GL LD5530R	Leadtrand	xxt30 xxt30R
LD7531	LD7531GL, LD7531PL	Leadtrend	xxP31
LD7531A	LD7531AGL	Leadtrend	xxP31A
LD7535/A	LD7535BL, LD7535GL, LD7535ABL, LD7535AGL	Leadtrend	xxP35-xxx35A
LD7550	LD7550BL, LD7550IL	Leadtrend	xxP50
LD7550B	LD7550BBL, LD7550BIL	Leadtrend	xxP50B
LD7551	LD7551BL/IL	Leadtrend	xxP51
LD7551C	LD7551CGL	Leadtrend	xxP51C
NX1049	XN1049TP	Xian-Innuovo	49xxx
OB2262	OB2262MP	On-Bright-Electronics	62xx
OB2263	OB2263MP	On-Bright-Electronics	63xx
PT4201	PT4201E23F	Powtech	4201
R7731	R7731GE/PE	Richtek	0Q=
R7731A	R7731AGE	Richtek	IDP=xx
SD4870	SD4870TR	Silan Microelectronics	4870
SF1530	SF1530LGT	SiFirst	30xxx
SG5701	SG5701TZ	System General	AAExx
SG6848	SG6848T, SG6848T1, SG6848TZ1, SG6848T2	Fairchild / ON Semi	AAHxx EAxxx
SG6858	SG6858TZ	Fairchild / ON Semi	AAIxx
SG6859A	SG6859ATZ, SG6859ATY	Fairchild / ON Semi	AAJFxx
SG6859	SG6859TZ	Fairchild / ON Semi	AAJMxx
SG6860	SG6860TY	Fairchild	AAQxx
SP6850	SP6850S26RG	Sporton Lab	850xx
SP6853	SP6853S26RGB, SP6853S26RG	Sporton Lab	853xx
SW2263	SW2263MP	SamWin
UC3863/G	UC3863G-AG6-R	Unisonic Technologies Co	U863 U863G
XN1049	XN1049, XN1049TP	Innuovo Microelectronics	49 xxx

 

 PWM controllers that use pin 3 differently.

When using the following PWM (PWM controllers), you should pay attention to pin 3, which can be used to organize protection - thermal or from overvoltage of the input voltage.
The frequency can be fixed at 65kHz, or set by the value of the capacitor at pin 3.
When replacing any microcircuits with analogs, carefully study the documentation. PDF files are packed in a RAR archive.

 

Name	Part Number	Fabricant	Marking
AP3105/V/L/R	AP3105KTR-G1, AP3105VKTR-G1, AP3105LKTR-G1, AP3105RKTR-G1	Diodes Incorporated	GHN GHO GHP GHQ
AP3105NA/NV/NL/NR	AP3105NAKTR-G1, AP3105NVKTR-G1, AP3105NLKTR-G1, AP3105NRKTR-G1	Diodes Incorporated	GKN GKO GKP GKQ
AP3125A/V/L/R	AP3125AKTR-G1, AP3125VKTR-G1, AP3125LKTR-G1, AP3125RKTR-G1	Diodes Incorporated	GLS GLU GNB GNC
AP3125B	AP3125BKTR-G1	Diodes Incorporated	GLV
AP3125HA/HB	AP3125HAKTR-G1, AP3125HBKTR-G1	Diodes Incorporated	GNP GNQ
AP31261	AP31261KTR-G1	Diodes Incorporated	GPE
AP3127/H	AP3127KTR-G1, AP3127HKTR-G1	Diodes Incorporated	GPH GSH
AP3301	AP3301K6TR-G1	Diodes Incorporated	GTC
FAN6862	FAN6862TY	Fairchild / ON Semi	ABDxx
FAN6863	FAN6863TY, FAN6863LTY, FAN6863RTY	Fairchild / ON Semi	ABRxx
HT2273	HT2273TP	HOT-CHIP	73xxx
LD7510/J	LD7510GL, LD7510JGL	Leadtrend	xxP10 xxP10J
LD7530/A	LD7530PL, LD7530GL, LD7530APL, LD7530AGL	Leadtrend	xxP30 xxxP30A
LD7532	LD7532GL	Leadtrend	xxP32
LD7532A	LD7532AGL	Leadtrend	xxP32A
LD7532H	LD7532HGL	Leadtrend	xxP32H
LD7533	LD7533GL	Leadtrend	xxP33
LD7536	LD7536GL	Leadtrend	xxP36
LD7536R	LD7536RGL	Leadtrend	xxP36R
LD7537R	LD7537RGL	Leadtrend	xxP37R
LD7539C GL	LD7539C GL	Leadtrend	xxP39C
ME8204	ME8204M6G	MicrOne	ME8204xx
NCP1250	NCP1250ASN65T1G, NCP1250BSN65T1G, NCP1250ASN100T1G, NCP1250BSN100T1G	ON Semiconductor	25xxxx
NCP1251	NCP1251ASN65T1G, NCP1251BSN65T1G, NCP1251ASN100T1G, NCP1251BSN100T1G	ON Semiconductor	5xxxxx
OB2273	OB2273MP	On-Bright-Electronics	73xx
R7735	R7735AGE, R7735HGE, R7735GGE, R7735RGE, R7735LGE	Richtek
UC3873/G	UC3873-AG6-R, UC3873G-AG6-R	Unisonic Technologies	U873 U873G

 

TCL L32S6300 TV with LCD LVW320ND1L, diagonal size 32 "(81 cm) 16: 9 format. The brightness of the screen, declared by the manufacturer, 240 cd / m2 is realized by LED backlight. Contrast - the ratio of maximum brightness to minimum, is at least 3000 : 1. The technology of manufacturing the screen of this TV model is realized with LED backlighting.
LVW320ND1L sensor and MainBoard TPD.NT72563.PB771 software realize HD image quality at 1366x768 pixels in 720p (HD Ready).
The L32S6300 TV is equipped with SMART software, built-in applications and the ability to work on the Internet. Internet connection can be made via Wi-Fi wireless connection. Supported media file formats: MP3, MPEG4, MKV, JPEG.
The power of the acoustic system of sound is 10 W (2x5 W), provided by two speakers. Uses the NICAM stereo signal processing system and the Sound Surround function.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, component, HDMI x3, USB x2, Ethernet (RJ-45), Wi-Fi. A headphone output is provided. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.

A power supply unit is used as part of the MainBoard.

Dimensions: with stand 734x476x184 mm, without stand 734x435x82 mm.

TV weight: with stand: 4.5 kg, without stand: 4.4 kg.

Attention! The LVW320ND1L panel of the TCL L32S6300 LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.