Friday, 16 April 2021

REPAIRING / SERVICING TV THOMSON T55FSE1170

Technical description and composition of the THOMSON T55FSE1170 TV, type of panel and modules used. Module composition.
Composition/Specifications
THOMSON T55FSE1170
LCD TV LED T55FSE1170 | Year of manufacture: 2018
Screen diagonal: 54.6" (139 cm)
Aspect ratio: 16:9
Resolution: 1920x1080
Refresh rate:     50Hz
LED backlight: Yes, Direct LED
Support HD: 1080p Full HD
Brightness: 290 cd/m2
Contrast: 4000:1
Viewing Angle: 178°
Pixel Response Time:     6.5 ms
Progressive scan: Yes
Digital tuner: DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2
Number of channels: 799
Teletext: there is
Multimedia: MP3, MPEG4, HEVC (H.265), Xvid, MKV, JPEG
Sound stereo: there is
Sound power: 16W (2x8W)
Acoustics: two speakers
Interface: AV, HDMI x2, USB x2
Headphone jack: yes
TV weight: 13 kg
Dimensions: with stand 1242x770x250 mm
without stand 1242x729x80 mm
AC power consumption: 100W
Find out more...
THOMSON T55FSE1170

THOMSON LED
Model: T55FSE1170

Chassis/Version: T.MS3663S

Panel: LVF550CSDX

LED driver (backlight): integrated into PSU

PWM LED driver: OB3365RP

MOSFET LED driver: MDF13N50

Power Supply (PSU): SHG6004C-101H

PWM Power: FA1A60N, FA6B20N

MOSFET Power: MMD60R580Q

MainBoard: T.MS3663S.782 1MS663E0S2A

MainBoard IC: CPU, SPI Flash, AUDIO, DC/DC

MainBoard: CDT-9NT372-RF01 & SAT
General advice about LCD LED TV repair
Possible problems

- THOMSON T55FSE1170 TV set doesn't turn on at all. No reaction to remote control or front panel controls. No indicator light is on or is not blinking.

In such cases the SHG6004C-101H power supply is usually the defective one. It is necessary to measure its output voltages, and if there are no such voltages, check the condition of the power switches (MMD60R580Q) of the converters and the rectifier diodes for possible short circuits.
At breakdowns in the secondary circuits of the inverter, usually it can crash in the short-circuit mode, and at short circuit in the power elements of the primary circuit most often the mains fuse or current sensor in the source of the key breaks.
Breakdown of Mos-Fet switches used in pulse sources is often caused by failures of other elements, for example, in PWM controller power supply circuit, in frequency-retaining or damping circuits, as well as in the Negative Feedback Stabilization. PWM microcircuits FA1A60N, FA6B20N are usually checked by replacement with the new ones, or known to be in good condition.

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

In some of these cases the malfunction is caused by the lack of display backlighting. The cause may sometimes be in the power supply of LEDs, but more often in their failure (breakdown or breakage), sometimes in violation of the contact connections of LED strips.
When trying to identify breaks in the LED strips, you should keep in mind that it is difficult to do without disassembling the panel. You need, for example, a current source to open the PN-junctions connected in series.

If THOMSON T55FSE1170 has no picture but sound, often the LVF550CSDX display backlight simply does not work. Moreover, in LED televisions, the LEDs inside the panel usually fail, less often the LED driver.
In such cases you can see a faintly visible image when external light hits the screen.

To replace the LEDs requires disassembly of the LCD panel LVF550CSDX - a process which requires a master of experience and skill. We do not recommend to perform such works by yourself to owners of TV sets and craftsmen who have no experience in LCD panel repair

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

If there is no image, but the backlight works - the screen becomes slightly lighter when you turn it on, and you can see the light through the holes in the body of the panel when the TV is open.
In this case the panel may be defective - damage to the strips, cables, for example, as a consequence of moisture after an unsuccessful washing of the screen, the T-CON board (Timing Controller) may be defective. But quite often the MainBoard T.MS3663S.782 is defective, and so is the software.
Then first it is necessary to check the panel power 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 normal limits, you need to trace with an oscilloscope the LVDS signals from MainBoard T.MS3663S.782, as well as synchronizing signals to driver stubs.

Filled or unsuccessfully washed LED TV screens can be repaired in about half of the cases, usually if there is no significant damage to the panel stubs and slats.

- Front panel LED blinks, TV set does not turn on, remote control is unresponsive.

Repair or diagnostic of the T.MS3663S.782 motherboard should begin with checking the stabilizers and power converters necessary to power the chips and matrix. If necessary, software (software) should be updated or replaced. Sometimes elements of MainBoard - CPU, SPI Flash, AUDIO, DC/DC need checking or replacement (if necessary). In cases where a BGA processor is used, its failure is usually detected by local heating method.

If you cannot tune to the terrestrial or cable TV channels, make sure the software is correct, and the supply voltages on the CDT-9NT372-RF01 & SAT tuner pins are correct. It is also necessary to control with an oscilloscope the presence of pulses of data exchange between the tuner and the processor via the I2C bus.

Remember! Attempts to repair your THOMSON T55FSE1170 TV set yourself, if you do not have the necessary skills and experience, is categorically not recommended and is fraught with negative consequences, up to the complete unrepairability of the device!

Refinement after repair of the backlight. SHG6004C-101H, OB3365RP. Information from the master.

Reduce backlight current from 410 mA to 250 mA - On the SHG6004C-101H board on pin 2 of ISET chip OB3365RP in parallel resistors R229 47 kOhm and R239 68 kOhm. Removed 68 kOhm resistor.
Driver current limitation. OB3365RP. 

General info.

To reduce the backlight current you can remove one of the resistors on pin 2 of the ISET chip OB3365RP, so that their total resistance increases in proportion to the reduced current in the LEDs.
More on MainBoard Repair

The appearance of the MainBoard T.MS3663S.782 is shown in the figure below:






T.MS3663S.782

MainBoard Appearance

SHG6004C-101H:

SHG6004C-101H

Main features of THOMSON T55FSE1170:

LVF550CSDX matrix (LED panel) is installed.
To power the LED backlight used converter, combined with a power supply, controlled by a PWM controller OB3365RP. MDF13N50 type switches are used as power elements of LED-driver.
Forming of necessary power supply voltages for all THOMSON T55FSE1170 TV set components is performed by the SHG6004C-101H power module or its analogues with the use of FA1A60N, FA6B20N chips and MMD60R580Q type power keys.
MainBoard - the main board (motherboard) is a module T.MS3663S.782, with the use of chips CPU, SPI Flash, AUDIO, DC / DC, and others.
The CDT-9NT372-RF01 & SAT tuner provides TV program reception and channel tuning.

 

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. 

 

NamePart NumberFabricantMarking
SG6849SG684965TZFairchild / ON SemiBBxx
SG6849SG6849-65T, SG6849-65TZSystem GeneralMBxx EBxx
SGP400SGP400TZ 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.

 

NamePart NumberFabricantMarking
AP3103AAP3103AKTR-G1Diodes IncorporatedGHL
AP8263AP8263E6R, A8263E6VRAiT SemiconductorS1xx
AT3263AT3263S6ATC Technology3263
CR6848CR6848SChip-Rail848H16
CR6850CR6850SChip-Rail850xx
CR6851CR6851SChip-Rail851xx
FAN6602RFAN6602RM6XFairchild / ON SemiACCxx
FS6830FS6830FirstSemi
GR8830GR8830CGGrenergy30xx
GR8836GR8836C, GR8836CGGrenergy36xx
H6849H6849NFHI-SINCERITY
H6850H6850NFHI-SINCERITY
HT2263HT2263MPHOT-CHIP63xxx
KP201
Kiwi Instruments
LD5530LD5530GL LD5530RLeadtrandxxt30 xxt30R
LD7531LD7531GL, LD7531PLLeadtrendxxP31
LD7531ALD7531AGLLeadtrendxxP31A
LD7535/ALD7535BL, LD7535GL, LD7535ABL, LD7535AGLLeadtrendxxP35-xxx35A
LD7550LD7550BL, LD7550ILLeadtrendxxP50
LD7550BLD7550BBL, LD7550BILLeadtrend xxP50B
LD7551LD7551BL/ILLeadtrendxxP51
LD7551CLD7551CGLLeadtrendxxP51C
NX1049XN1049TPXian-Innuovo49xxx
OB2262OB2262MPOn-Bright-Electronics62xx
OB2263OB2263MPOn-Bright-Electronics63xx
PT4201PT4201E23FPowtech4201
R7731R7731GE/PERichtek0Q=
R7731AR7731AGERichtekIDP=xx
SD4870SD4870TRSilan Microelectronics4870
SF1530SF1530LGTSiFirst30xxx
SG5701SG5701TZSystem GeneralAAExx
SG6848SG6848T, SG6848T1, SG6848TZ1, SG6848T2Fairchild / ON SemiAAHxx EAxxx
SG6858SG6858TZFairchild / ON SemiAAIxx
SG6859ASG6859ATZ, SG6859ATYFairchild / ON SemiAAJFxx
SG6859SG6859TZFairchild / ON SemiAAJMxx
SG6860SG6860TYFairchildAAQxx
SP6850SP6850S26RGSporton Lab850xx
SP6853SP6853S26RGB, SP6853S26RGSporton Lab853xx
SW2263SW2263MPSamWin
UC3863/GUC3863G-AG6-RUnisonic Technologies CoU863 U863G
XN1049XN1049, XN1049TPInnuovo Microelectronics49 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.

 

NamePart NumberFabricantMarking
AP3105/V/L/RAP3105KTR-G1, AP3105VKTR-G1, AP3105LKTR-G1, AP3105RKTR-G1Diodes IncorporatedGHN GHO GHP GHQ
AP3105NA/NV/NL/NRAP3105NAKTR-G1, AP3105NVKTR-G1, AP3105NLKTR-G1, AP3105NRKTR-G1Diodes IncorporatedGKN GKO GKP GKQ
AP3125A/V/L/RAP3125AKTR-G1, AP3125VKTR-G1, AP3125LKTR-G1, AP3125RKTR-G1Diodes IncorporatedGLS GLU GNB GNC
AP3125BAP3125BKTR-G1Diodes IncorporatedGLV
AP3125HA/HBAP3125HAKTR-G1, AP3125HBKTR-G1Diodes IncorporatedGNP GNQ
AP31261AP31261KTR-G1Diodes IncorporatedGPE
AP3127/HAP3127KTR-G1, AP3127HKTR-G1Diodes IncorporatedGPH GSH
AP3301AP3301K6TR-G1Diodes IncorporatedGTC
FAN6862FAN6862TYFairchild / ON SemiABDxx
FAN6863FAN6863TY, FAN6863LTY, FAN6863RTYFairchild / ON SemiABRxx
HT2273HT2273TPHOT-CHIP73xxx
LD7510/JLD7510GL, LD7510JGLLeadtrendxxP10 xxP10J
LD7530/ALD7530PL, LD7530GL, LD7530APL, LD7530AGLLeadtrendxxP30 xxxP30A
LD7532LD7532GLLeadtrendxxP32
LD7532ALD7532AGLLeadtrendxxP32A
LD7532HLD7532HGLLeadtrendxxP32H
LD7533LD7533GLLeadtrendxxP33
LD7536LD7536GLLeadtrendxxP36
LD7536RLD7536RGLLeadtrendxxP36R
LD7537RLD7537RGLLeadtrendxxP37R
LD7539C GLLD7539C GLLeadtrendxxP39C
ME8204ME8204M6GMicrOneME8204xx
NCP1250NCP1250ASN65T1G, NCP1250BSN65T1G, NCP1250ASN100T1G, NCP1250BSN100T1GON Semiconductor25xxxx
NCP1251NCP1251ASN65T1G, NCP1251BSN65T1G, NCP1251ASN100T1G, NCP1251BSN100T1GON Semiconductor5xxxxx
OB2273OB2273MPOn-Bright-Electronics73xx
R7735R7735AGE, R7735HGE, R7735GGE, R7735RGE, R7735LGERichtek
UC3873/GUC3873-AG6-R, UC3873G-AG6-RUnisonic TechnologiesU873 U873G

 


THOMSON T55FSE1170 LED TV with LVF550CSDX LCD display, measuring 54.6" (139 cm) diagonally in 16:9 aspect ratio. 290 cd/m² of claimed brightness is provided by an advanced LED backlight with a maximum brightness to minimum brightness ratio (contrast ratio) of at least 4000:1. In the LCD-panel uses direct backlighting with a back arrangement of LEDs - Direct LED.
LVF550CSDX matrix and MainBoard T.MS3663S.782 software implement an image in high quality HD with 1920x1080 pixels resolution in 1080p (Full HD) graphic decomposition. Supports multimedia formats: MP3, MPEG4, HEVC (H.265), Xvid, MKV, JPEG.
The sound system capacity of 16 W (2x8 W) is provided by two speakers. NICAM stereo processing system and Sound Surround surround sound function are used.
External interface (connection with other devices) is supported by standard input and output connectors: antenna input (RF), AV, HDMI x2, USB x2. There is a headphone jack. The digital tuner has DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.

The power consumed by the TV in mains mode is 100 watts. SHG6004C-101H power supply.

Overall dimensions: with stand 1242x770x250 mm, without stand 1242x729x80 mm.

The TV weight is 13 kg.

Warning. The panel on the LVF550CSDX LED TV THOMSON T55FSE1170 is an expensive and fragile part of the TV.
Avoid any kind of impact on the glass and pressure on the screen surface to avoid damaging the LED panel!
It is also not safe to get liquid on the screen. Sometimes one drop is enough if it drips down the glass onto the cables and the TV becomes unrepairable.