Friday, 27 March 2020

REPAIR / SERVICING TV TOSHIBA 32AV655PR

Technical description and composition of the TOSHIBA 32AV655PR TV, type of panel and applicable modules. The composition of the modules.
Toshiba
Model: 32AV655PR
Panel: LK315T3LA51
Inverter (backlight): RDENC2590TPZA
PWM Inverter: BD9897FS (32 pin)
MOSFET Inverter: 9962AGH
Power Supply (PSU): DPS-219DP A 2950238305
PWM Power: DAP015D, 1607B (PFC), A6069H
MOSFET Power: 2SK3569, P10NK60ZFP, FDD8880
MainBoard: PE0772 V28A001020A1
IC MainBoard: MST6B885GL-LF-3, H5DU1262GTR-FBC, Atmel 26DF161A, 24C08, TAS5705
Tuner: TAEA-G059D
Specifications 32AV655PR
TOSHIBA 32AV655PR
General recommendations for repairing TV LCD
Possible malfunctions
- The TOSHIBA 32AV655PR TV does not turn on, does not respond to the remote control and the control panel buttons, does not blink with any indicators.
With such manifestations, for example, the DPS-219DP power module may be faulty. First of all, check the standby power converter A6069H. Next, you need to make sure the output voltage of other converters (PFC and the main source) is available, check the power switches (2SK3569, P10NK60ZFP, FDD8880) and rectifier diodes for a possible partial or complete breakdown.
In case of breakdowns in the secondary circuits, the converter can emergencyly operate in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse usually breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. It can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power switch can be PWM controllers (PWM) DAP015D, 1607B (PFC). It is usually checked by replacing with obviously working ones.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
These manifestations can be triggered by a power module, or by defects in the inverter, as well as a distortion of the currents in the lamps due to their uneven wear. If all the electrolytic capacitors of the filter according to the inverter power supply are serviceable, you should make sure that the lamps are working, then you need to check the converter keys and the secondary windings of the transformers.
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 indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the PE0772 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). If it is not possible to replace the MB board (SSB), you need to check the health of its elements - MST6B885GL-LF-3, H5DU1262GTR-FBC, Atmel 26DF161A, 24C08, TAS5705. Defective components should be replaced.
In the absence of tuning to the channels of on-air or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltages at the terminals of the TAEA-G059D tuner. It is also necessary to check the presence of pulses of data exchange between the tuner and the processor via the I2C bus using an oscilloscope.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Entrust repair to professionals with sufficient experience in the field of repair of electronic equipment.


The appearance of MainBoard PE0772 is shown in the figure below:
PE0772
PE0772 can be used in TVs:
TOSHIBA 32AV655PR (Panel LK315T3LA51), TOSHIBA 40LV655PR (Panel LTA400HA11).
Main features of the TOSHIBA 32AV655PR device:
Installed matrix (LCD panel) LK315T3LA51.
To power the backlight, an inverter RDENC2590TPZA is used, it is controlled by the BD9897FS PWM controller (32 pin). As power elements of the inverter, keys of the type 9962AGH are used.
The necessary supply voltages for all nodes of the TOSHIBA 32AV655PR TV are generated by the DPS-219DP power module or its analogs using DAP015D, 1607B (PFC), A6069H microchips and 2SK3569, P10NK60ZFP, FDD8880 type power switches.
MainBoard - the main board (motherboard) is a PE0772 module, using microcircuits MST6B885GL-LF-3, H5DU1262GTR-FBC, Atmel 26DF161A, 24C08, TAS5705 and others.
The TAEA-G059D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: SHARP
Model: LK315T3LA51
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: ASV, Normally Black, Transmissive
Active Area: 697.68x392.26 mm
Display Colors: 16.7M (8-bit)
Lamp Type: CCFL


TOSHIBA 32AV655PR LCD TV with LK315T3LA51 LCD display, 32 "(81 cm) diagonal size in 16: 9 format. 500 cd / m² screen brightness is provided by CCFL (EEFL) fluorescent lamps. Dynamic contrast ratio of 50,000: 1 is achieved by special control of operation 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 occurs it in the standards 480i, 480p, 576i, 576p, 720p, 1080i Supported media file formats: JPEG.
The power of the sound system 20 W (2x10 W) provides two speakers. The audio processing system NICAM STEREO is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, S-Video, component, SCART x2, RGB, VGA, HDMI x3, USB. 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, 1280x1024, 1360x768.
Overall dimensions: with stand 786x567x286 mm, without stand 786x525x85 mm.
TV Weight: with stand: 13.5 kg, without stand: 12.2 kg.
Attention! The TOSHIBA 32AV655PR LCD TV panel LK315T3LA51 is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!