Technical description and composition of the THOMSON 32M71NH20 TV, panel type and modules used. The composition of the modules.THOMSON
Model: 32M71NH20
Chassis / Version: MT01
Panel: LC420WX7 (SL) (A1) // LK315T3LZ54
T-CON: 6870C-0150B Ver.1.0 TPS65162
Power Supply (PSU): JSK4338-007A
PWM Power: L6563 (PFC 14pin), ICE3B0565, L6599D
MainBoard: 40-MT01TI-MAD2XG KB-6160 ULB800057A 80023377MA0082
IC MainBoard: MT8202 MT8293AE S29AL016D70TFI02 ULB800057A TEDE9-2C2B
Tuner: TEDE9-2C2B
Control: 40-LD40V8-RMC1XG AS1213
Specifications 32M71NH20
THOMSON 32M71NH20
General recommendations for TV LCD repair
Possible manifestations of malfunctions
- THOMSON 32M71NH20 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 the remote control and control buttons.
With similar manifestations, a malfunction is most likely found in the JSK4338-007A power module. It is then necessary to measure its output voltages and, in their absence, the power switches and rectifier diodes of the converters should be checked for the probability of 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 often breaks 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 the PWM controller, in frequency setting or damper circuits, as well as in negative feedback stabilization. PWM microcircuits (PWM) L6563 (PFC 14pin), ICE3B0565, L6599D 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 immediately disappears
These manifestations can be triggered by the power module, or by defects in the inverter, as well as by skewed currents in the lamps due to their uneven wear. After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, you should ring the power switches in its converter for breakdown and the secondary windings of the transformers for an open.
Sometimes, for diagnostic purposes, it is necessary to disable the inverter protection. In such cases, special care must be taken during work, and the protective circuits must be restored immediately after the repair is completed.
- 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 40-MT01TI-MAD2XG 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). Sometimes it is necessary to check or replace (if necessary) elements of the MainBoard - MT8202 MT8293AE S29AL016D70TFI02 ULB800057A TEDE9-2C2B. In cases where a BGA processor is used, its malfunction is usually detected by the local warm-up method.
If the TV operates normally from external devices but does not tune to TV channels, the TEDE9-2C2B 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.
The lack of an image in the presence of a signal from THOMSON 32M71NH20 is often caused by a malfunction of the display backlight. Moreover, the problem can be both inside the LCD panel (matrix) LC420WX7 (SL) (A1), for example, a malfunction of CCFL (EEFL) lamps, and outside in their power source - the inverter.
Without backlighting, sometimes you can see a barely noticeable image with a certain successful hit of external light on the screen.
Often, to repair the backlight, disassembly of the LC420WX7 (SL) (A1) LCD panel is required - a painstaking process that requires increased attention and accuracy from the master. In such cases, there is a possibility, with the slightest negligence, to damage the glass or loops and the TV may become unrepairable.
We strongly do not recommend doing such work to owners of TVs and craftsmen who do not have experience in repairing LCD panels! Moreover, at home (at the owner's home).
If there is no image in the presence of backlight, the screen becomes slightly lighter when turned on, and if the TV is open, the light from the lamps can be seen through the holes in the panel case.
In this case, there may be a malfunction inside the panel, damage to strips, loops, the T-CON board (Timing Controller) may be defective. But the main board MainBoard 40-MT01TI-MAD2XG often turns out to be faulty, a software failure is also possible.
In such cases, the master first of all needs to check the main supply voltage of the panel at the LVDS connector, the fuses on the T-CON board or the panel brackets, as well as the supply and reference voltages for line and column drivers - VGH, VGL, Vcom.
If all of the above measurements are within the normal range, then the oscilloscope should track the passage of LVDS signals from MainBoard 40-MT01TI-MAD2XG, as well as synchronizing signals from T-CON to loops with drivers.
Owners and users of the THOMSON 32M71NH20 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!
DOWNLOAD FIRMWARE FOR SPI FLASH -----------> THOMSON 32M71NH20 MT01, Main: 40-MT01TI-MAD2XG
The appearance of the MainBoard 40-MT01TI-MAD2XG is shown in the figure below:40-MT01TI-MAD2XG
External view of the power supply
The main features of the THOMSON 32M71NH20 device:
Installed matrix (LCD panel) LC420WX7 (SL) (A1) or LK315T3LZ54.
Matrix control uses the Timing Controller (T-CON) 6870C-0150B.
The formation of the necessary supply voltages for all nodes of the THOMSON 32M71NH20 TV is carried out by the JSK4338-007A power module, or its analogs using L6563 (PFC 14pin), ICE3B0565, L6599D microcircuits.
MainBoard - the main board (motherboard) is a 40-MT01TI-MAD2XG module, using MT8202 MT8293AE S29AL016D70TFI02 ULB800057A TEDE9-2C2B chips and others.
The TEDE9-2C2B tuner provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: LG.Philips LCD
Model: LC420WX7-SLA1
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1366x768, WXGA
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 930.25x523.01 mm
Surface: Antiglare (Haze 13%), Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit), CIE1931 73%
Response Time: 10 (Tr + Td); 5 (G to G)
Frequency: 60Hz
Lamp Type: EEFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V
THOMSON 32M71NH20 LCD TV with LC420WX7 (SL) (A1) LCD, 32 "(81 cm) 16: 9. Screen brightness of 500 cd / m² provided by CCFL (EEFL) backlighting. Dynamic contrast ratio 5000: 1 achieved by special control of the backlight depending on the brightness of the scene.It is possible to view in high quality HD at a resolution of 1366x768 pixels in the standard 720p (HD Ready) .Input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Digital signal formation (graphic format) produced in 480i, 480p, 576i, 576p, 720p, 1080i standards.
Speaker power 15 W (2x7.5 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, S-Video, SCART, RGB, HDMI.
Attention! The LC420WX7 (SL) (A1) panel of a THOMSON 32M71NH20 LCD TV is the most expensive component.
Avoid hitting the glass and putting pressure on the screen surface to avoid irreversible damage to the LCD panel!
