Monday, 30 March 2020

REPAIR / SERVICING TV TOSHIBA 37WL55R

Technical description and composition of the TOSHIBA 37WL55R TV, type of panel and applicable modules. The composition of the modules.
Toshiba
Model: 37WL55R
Chassis / Version: PD2131
Panel: LC370WX1 (SL) (03)
Lamp backlight: 20 LAMP EEFL
T-CON: 6870C-0060F LC370WX1 / LC320W01
Inverter (backlight): 6632L-0201B KLS-EE37CI-M & 6632L-0202B KLS-EE37CI-S
Power Supply (PSU): PD2105 A-2 & PD2105 A-1
MainBoard: PD2131 A5A001390010 & PD2095
IC MainBoard: CPU: FLI8532-LF, EEPROM: M24128BW
Tuner: ENG37A06GF
Specifications 37WL55R
TOSHIBA 37WL55R
General recommendations for repairing TV LCD
Possible malfunctions
- The TOSHIBA 37WL55R does not turn on. There are no signs of operability. The indicators on the front panel do not light or flash, the TV does not respond to the remote control and control buttons.
With similar manifestations, in some cases, the PD2105 power module is faulty. It is necessary to measure its output supply voltage, and in case of their absence, check the serviceability of the power switches of the converters and rectifier diodes for the probability of breakdown in semiconductor PN junctions.
In case of any breakdowns in the secondary circuits, the converter can operate in emergency short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key more often breaks.
Breakdown of power switches (MosFet) in pulsed sources is sometimes caused by malfunctions of other circuit elements, for example, in circuits supplying a PWM controller, frequency-setting or damper ones, as well as in negative feedback circuits (OOS) of stabilization. PWM controllers (PWM), if they do not have visible damage to the chassis and open short circuit between the terminals, are usually checked by replacement.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
The defect can be caused by problems in the nodes or elements of the backlight of the display, or in the power supply of the lamps or the inverter.After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, you must ring in its converter power keys for breakdown and secondary windings of transformers for an open.
If in diagnosing a malfunction, it is necessary to disable the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required during work, and after they are finished, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the PD2131 motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). In cases of attempts to repair the MB board (SSB), it is necessary to check the health of its elements - CPU: FLI8532-LF, EEPROM: M24128BW which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its conclusions with the board (it is diagnosed by heating).
The malfunction of the ENG37A06GF tuner is established after checking the software and all the supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be controlled by an oscilloscope.
Attention! For users and owners of 37WL55R TVs who do not have the appropriate qualifications, knowledge and experience, we categorically do not recommend attempting self-repair in order to avoid negative consequences that could lead to complete non-repairability of the device.


FIRMWARE FOR SPI FLASH  ----------->   TOSHIBA 37WL55R, Main: PD2131


 The appearance of the MainBoard PD2131 is shown in the figure below:
PD2131
PD2131 can be used in TVs:
TOSHIBA 27WL55R (Panel V270W1-L04), TOSHIBA 37WL55R (Panel LC370WX1 (SL) (03)).
Key Features of the TOSHIBA 37WL55R:
The matrix (LCD panel) LC370WX1 (SL) (03) is installed.
The matrix control uses the Timing Controller (T-CON) 6870C-0060F.
To power the backlight used inverter 6632L-0201B.
The necessary supply voltages for all nodes of the TOSHIBA 37WL55R TV are generated by the PD2105 power supply module or its analogs.
MainBoard - the main board (motherboard) is a PD2131 module, using CPU chips: FLI8532-LF, EEPROM: M24128BW and others.
The ENG37A06GF tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG.Philips LCD
Model: LC370WX1-SL03
Type: a-Si TFT-LCD, Panel
Diagonal size: 37 inch
Resolution: 1366x768, WXGA
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 819.6x460.8 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 800: 1
Display Colors: 16.7M (8-bit)
Response Time: 8/10 (Tr / Td); 8 (G to G)
Frequency: 60Hz
Lamp Type: 20 pcs EEFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V

 Trademark: TOSHIBA, Model: 37WL55R.
Briefly from the TV: LCD, 37 ", 1366x768, 720p HD, sound: 20 watts.
The composition includes MainBoard PD2131 A5A001390010 & PD2095 and LCD-panel LC370WX1 (SL) (03).
Power Supply Unit (PSU) PD2105 A-2 & PD2105 A-1 power Supply.
TOSHIBA 37WL55R LCD TV with LC370WX1 LCD, 37 "(94 cm) diagonal display in 16: 9 format. 500 cd / m² screen brightness is provided by CCFL (EEFL) fluorescent lamps. The ratio of maximum brightness to minimum (contrast) is 600: 1. It is possible to view images in high quality HD at a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation takes place in the standard max 480i, 480p, 576i, 576p, 720p, 1080i.
The power of the acoustic system of sound 20 W (2x10 W) provide two speakers. It uses a NICAM stereo signal processing system and Sound Surround.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV x3, audio x4, component, VGA. An output for connecting headphones is provided. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector is used on the TV case, this interface supports resolutions: 640x480, 800x600, 1024x768.
Overall dimensions: with stand 916x716x300 mm, without stand 916x661x109 mm.
TV Weight: with stand: 28.5 kg, without stand: 23.5 kg.
Attention! The TOSHIBA 37WL55R LCD TV panel LC370WX1 (SL) (03) is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!