Technical description and composition of the TCL L43P6US TV, panel type and modules used. The composition of the
modules.
TCL LED
Model: L43P6US
Chassis / Version: MS6586
Panel: T430QVN03.0 LVU430NEBL
LED backlight: 43P6-UD-HS
T-CON: 55T32-COF CTRL BD
LED driver (backlight): integrated into PSU
PWM LED driver: DIP-16
MOSFET LED driver: TO-252
Power Supply (PSU): 40-L121H4-PWB1CG
PWM Power: PWM SOT23-6
MOSFET Power: TO-220
MainBoard: 40-MS86L1-MAA2HG
IC MainBoard: CPU: MSD6586PYE-8-SW, eMMC: THGBMDG5D1LBAIL, DRAM, AUDIO, DC / DC
Tuner: DVB-T2 & SAT
Specifications L43P6US
TCL L43P6US
General recommendations for TV LCD LED repair
Possible manifestations of defects
- TV TCL L43P6US does not turn on and does not give any signs of turning on, does not respond to control buttons and to the remote control.
Most likely, in this case, the main switching power supply (SMPS) 40-L121H4-PWB1CG is faulty. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, the serviceability of the power switches (TO-220) and rectifier diodes should be checked for a possible breakdown (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 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 the image may appear for a second when turned on and disappear immediately.
Often in such cases, there is no backlighting of the LED panel. 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.
Without a special current source, it is impossible to check the line of series-connected LEDs, and it is unsafe for them to use any voltage sources over 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 broken through in the K / Z.
If TCL L43P6US has no picture, but there is sound, often the backlight of the T430QVN03.0 display 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 T430QVN03.0 - 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 the 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 the main board MainBoard 40-MS86L1-MAA2HG 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 MainBoard 40-MS86L1-MAA2HG, as well as synchronization 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 turn on, the indicator signals the standby or operating mode, or blinks.
Repair or diagnostics of the 40-MS86L1-MAA2HG 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). If it is not possible to replace the MB (SSB) board, you need to check the serviceability of its elements - CPU, eMMC, DRAM, AUDIO, DC / DC. Defective components must be replaced.
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.
I remind users again! Attempts to repair the TCL L43P6US TV yourself without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
The appearance of the MainBoard 40-MS86L1-MAA2HG is shown in the figure below:
40-MS86L1-MAA2HG
External view of the power supply
The main features of the TCL L43P6US device:
Installed matrix (LED-panel) T430QVN03.0 LVU430NEBL.
Matrix control uses Timing Controller (T-CON) 55T32-COF.
To power the backlight LEDs, a converter combined with a power supply is used, controlled by a DIP-16 PWM controller. TO-252 switches are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the TCL L43P6US TV is carried out by the 40-L121H4-PWB1CG power module, or its analogs using PWM SOT23-6 microcircuits and TO-220 type power switches.
MainBoard - the main board (motherboard) is a 40-MS86L1-MAA2HG module, using CPU chips: MSD6586PYE-8-SW, eMMC: THGBMDG5D1LBAIL, DRAM, AUDIO, DC / DC and others.
The DVB-T2 & SAT tuner provides reception of television programs and tuning to channels.
TCL L43P6US TV with LCD T430QVN03.0, diagonal size 42.5 "(108 cm) 16: 9 format. The brightness of the screen, declared by the manufacturer, 280 cd / m2 is realized by LED backlight. Contrast - the ratio of maximum brightness to minimum, is not less than 4000: 1. The technology of production of the screen of this TV model is realized with LED backlighting.
T430QVN03.0 sensor and MainBoard 40-MS86L1-MAA2HG software are capable of realizing images in the highest UHD quality at 3840x2160 pixels in 4K UHD, HDR. Image processing is performed using modern High Dynamic Range (HDR) technology with an extended range of brightness gradations.
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 |
The L43P6US TV has built-in SMART software and pre-installed Linux 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. Uses NICAM stereo processing system and Sound Surround function.
An external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, 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 MPEG4, DVB-C, DVB-T2, DVB-S2 standards.
The TV uses a 40-L121H4-PWB1CG power supply.
Dimensions: with stand 961x607x232 mm, without stand 961x562x73 mm.
TV weight: with stand: 8.6 kg, without stand: 8.4 kg.
Attention! TCL L43P6US LED TV panel T430QVN03.0 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
Once again, I remind users and TV owners.
Self-repair attempts can have serious negative consequences, up to complete non-repairability.