Technical description and composition of the THOMSON T42E97DHU TV, panel type and modules used. The composition of the modules.THOMSON LED
Model: T42E97DHU
Chassis / Version: MSD209
Panel: LC420EUD // K420B1CE10
T-CON: V420H2-XC01
LED driver (backlight): KLD + L080E12-0
Power Supply (PSU): KPS-L180C3-01
PWM Power: FSFM300, FAN7530, FSFR1700
MOSFET Power: 2SK4108
MainBoard: MSD209 REV-01
IC MainBoard: CPU: MSD309, Flash S25FL128PIF, ATMLH018 2FB (24C512)
Tuner: TDTC-G311D
Specifications T42E97DHU
THOMSON T42E97DHU
General recommendations for TV LCD LED repair
Possible manifestations of defects
- THOMSON T42E97DHU 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.
In some of these cases, the fault is detected in the KPS-L180C3-01 power supply module. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches (2SK4108) 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 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, which can disable it in key mode, or provoke an excess of the maximum current or voltage values. These can be circuits supplying the PWM controller, damper or frequency setting circuits, or OOS (negative feedback) elements in the stabilization circuit. PWM controllers (PWM) FSFM300, FAN7530, FSFR1700, in the absence of external damage and a short circuit between the terminals, are checked by replacing them with known good ones.
- 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 malfunction in most of these cases is found in the nodes and elements of the LED panel backlight. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
To check the health of the LED circuit, it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED separately with a simple Chinese multimeter (powered by 9 volts) in the P-N transition test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black one to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. The serviceability of the PN junction of the Zener diode indirectly indicates the serviceability of the LED-a.
If THOMSON T42E97DHU has no picture, but there is sound, often the LC420EUD 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 LC420EUD 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 you can see light through the holes in the panel case.
In this case, the panel may also be faulty - damage to the 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 MSD209 often turns out to be faulty, a software failure is also possible.
Then, first of all, it is necessary 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 the MainBoard MSD209 with an oscilloscope, 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 TV does not turn on, the indicator signals the standby or operating mode, or blinks.
Repair or diagnostics of the MSD209 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). Complicated MB (SSB) repair is possible only in the conditions of a service center with the necessary equipment. Checking or replacing CPU elements: MSD309, Flash S25FL128PIF, ATMLH018 2FB (24C512) 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.
The malfunction of the TDTC-G311D tuner is established after checking the software and all supply voltages at its outputs. The data exchange of the tuner with the processor via the I2C bus can be monitored with an oscilloscope.
Remember! Attempts to self-repair the THOMSON T42E97DHU TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> THOMSON T42E97DHU Chassis MSD209.
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> KPS-L180C3-01 Power supply.
DOWNLOAD FIRMWARE FOR SPI FLASH -----------> THOMSON T42E97DHU, Panel: LC420EUD
The appearance of the MainBoard MSD209 is shown in the figure below:MSD209
External view of the power supply
The main features of the THOMSON T42E97DHU device:
Installed matrix (LED panel) LC420EUD or K420B1CE10.
Matrix control uses Timing Controller (T-CON) V420H2-XC01.
The LED driver KLD + L080E12-0 is used to power the backlight LEDs.
The formation of the necessary supply voltages for all nodes of the THOMSON T42E97DHU TV is carried out by the KPS-L180C3-01 power module, or its analogs using FSFM300, FAN7530, FSFR1700 microcircuits and 2SK4108 power switches.
MainBoard - the main board (motherboard) is an MSD209 module, using CPU chips: MSD309, Flash S25FL128PIF, ATMLH018 2FB (24C512) and others.
Tuner TDTC-G311D provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LC420EUD-FFF1
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: IPS, Normally Black, Transmissive
Active Area: 927.94x521.96 mm
Surface: Antiglare (Haze 1%), Hard coating (2H)
Brightness: 400 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 1.06B (8-bit + Dithering), CIE1931 72%
Response Time: 5 (G to G); 8 (MPRT)
Frequency: 120Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (2 ch, 10-bit), 92 pins
Voltage: 12.0V
LED TV THOMSON T42E97DHU with LCD LC420EUD, diagonal size 42 "(107 cm) 16: 9 format. The declared brightness of the screen of 450 cd / m2 is provided by modern LED backlighting. : 1. The LCD panel uses Edge LED backlighting The design and technical capabilities of the TV provide for viewing in high quality HD at a resolution of 1920x1080 pixels in graphic resolution according to the standard 1080p (Full HD). The input high-frequency or video signal is decoded into analog systems PAL, SECAM, NTSC Digital signal formation (graphic format) is performed in 480i, 480p, 576i, 576p, 720p, 1080i, 1080p standards.
Speaker power of 10 W (2x5 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), SCART, VGA, HDMI x4, USB x2. A headphone jack is provided. A standard VGA (D-Sub 15) connector is used to connect a laptop or computer. This interface supports resolutions: 640x480, 800x600, 1024x768.
Attention! The LC420EUD panel of the THOMSON T42E97DHU 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.