Monday 30 March 2020

REPAIR / SERVICING TV TOSHIBA 37AV605P

Technical description and composition of the TOSHIBA 37AV605P TV, type of panel and applicable modules. The composition of the modules.
Toshiba
Model: 37AV605P 37AV605PR
Chassis / Version: 715G3368-1
Panel: LC370WXN (SB) (B1)
T-CON: 6870C-0240C
Inverter (backlight): 6632L-0541A PPW-EE37HD-0 (T)
Power Supply (PSU): 715G3368-1
PWM Power: A6069H, FAN7529, L6599D
MOSFET Power: 20N60C3, 2SK4097
MainBoard: 715G3385-1
IC MainBoard: Cpu: MST9A885GL-LF, Flash: MX25L3205, Eeprom: 24C32WP
Tuner: TAFT-S710D
Specifications 37AV605P
TOSHIBA 37AV605P
General recommendations for repairing TV LCD
Possible manifestations of defects
- The TOSHIBA 37AV605P does not turn on at all. There is no reaction to the remote control and control buttons from the front panel. Indicator lights do not light or flash.
Most likely in this case, the main switching power supply (IPS) 715G3368-1 is faulty. It is necessary to measure its output voltages and, if they are absent, to check the short circuit probability in the converters power switches (20N60C3, 2SK4097) and rectifier diodes.
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.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM chips A6069H, FAN7529, L6599D are usually checked by replacing with new ones, or obviously working.
- There is no image, there is sound, it reacts to the remote control, channels are switched. In some cases, the image appears when you turn on and immediately disappears.
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 blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the 715G3385-1 motherboard should begin by checking the stabilizers and power converters needed to power the microcircuits and matrix. If necessary, update or replace the software (software). In cases of attempts to repair the MB (SSB) board, it is necessary to check the health of its elements - Cpu: MST9A885GL-LF, Flash: MX25L3205, Eeprom: 24C32WP 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 TAFT-S710D tuner is established after checking the software and all supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be controlled by an oscilloscope.
Once again, remind users! Attempts to independently repair the TOSHIBA 37AV605P TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!





Repair MainBoard
The appearance of the MainBoard 715G3385-1 is shown in the figure below:
715G3385-1
715G3385-1 can be used in TVs:
TOSHIBA 26AV605PR (Panel LTA260AP02 004), TOSHIBA 32AV605PR (Panel LK315LA51 75014913), TOSHIBA 32AV613DG (Panel LC320WXN-SBA1), TOSHIBA 37AV605P 37AV605PR (Panel LC370WXN (SB)(B1)).
The appearance of the power supply
Main features of the TOSHIBA 37AV605P device:
Installed matrix (LCD panel) LC370WXN (SB) (B1).
The matrix control uses the Timing Controller (T-CON) 6870C-0240C.
An inverter 6632L-0541A is used to power the backlight.
The necessary supply voltages for all nodes of the TOSHIBA 37AV605P TV are generated by the 715G3368-1 power module or its analogs using A6069H, FAN7529, L6599D microcircuits and power switches of the 20N60C3, 2SK4097 type.
MainBoard - the main board (motherboard) is a 715G3385-1 module using Cpu microcircuits: MST9A885GL-LF, Flash: MX25L3205, Eeprom: 24C32WP and others.
The TAFT-S710D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC370WXN-SBB1
Type: a-Si TFT-LCD, Panel
Diagonal size: 37 inch
Resolution: 1366x768, WXGA
Active Area: 819.6x460.8 mm
Frequency: 60Hz

Brand: TOSHIBA, Model: 37AV605P.
Shortly from the TV: LCD, 37 ", 1366x768, 720p HD, sound: 40W, HDMI connectors: 3.
The composition uses MainBoard 715G3385-1 and LCD-panel LC370WXN (SB) (B1).
Power Supply Unit (PSU) 715G3368-1 power Supply.
TOSHIBA 37AV605P LCD TV with LC370WXN LCD, 37 "(94 cm) diagonal display in 16: 9 format. 500 cd / m² screen brightness is provided by CCFL (EEFL) fluorescent lamps. Dynamic contrast ratio of 23000: 1 is achieved by special operation control 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 in standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p.
The power of the acoustic system of sound 40 W (2x20 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, component, SCART x2, RGB, VGA, HDMI x3. 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, 1360x768.
The power consumed by the TV in the operating mode from the network is 200 watts.
Overall dimensions: with stand 902x637x293 mm, without stand 902x591x95 mm.
TV Weight: with stand: 17.1 kg, without stand: 13.2 kg.
Attention! The TOSHIBA 37AV605P LCD TV panel LC370WXN (SB) (B1) is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!