Friday, 27 March 2020

REPAIR / SERVICING TV TOSHIBA 32AV501PR

Technical description and composition of the TOSHIBA 32AV501PR TV, type of panel and applicable modules. The composition of the modules.
Toshiba
Model: 32AV501PR
Chassis / Version: 32AV500
Panel: LK315T3LA31
Inverter (backlight): 75012525
Mainboard: PE0484
IC MainBoard: TDA8891H1 / N1B TDA15451HV / N1B00
Tuner: TAEA-G081D
Appearance
TOSHIBA 32AV501PR
General recommendations for repairing TV LCD
It is advisable to start the diagnosis of a malfunction of the TOSHIBA 32AV501PR TV, like all others, with an external examination of possible changes, both external and internal elements. Many visible signs make it possible to determine the future direction of troubleshooting and localization of the defect. Electrolytic capacitors of filters with a swollen casing, as well as ring cracks formed in the soldered leads of heating elements, or a layer of coal on burnt resistors sometimes tell the repairman the causes of the malfunction and possible consequences.
Malfunctions of the power module can be expressed in different ways, for example, the TOSHIBA 32AV501PR does not turn on at all and the control lamps on its front panel do not light up and do not blink, there are no signs of operability. If the mains fuse is broken in the power supply, in most cases a breakdown of the power switch is detected, which can be integrated with the PWM controller, or a separate field-effect transistor can be used. The rectifier bridge diodes and the electrolytic capacitor of the mains rectifier filter should also be checked.
As a rule, the keys of flyback converters, which use an N-Fet field effect transistor on a separate radiator, or integrated with a PWM controller in a single chip, are reliable enough and rarely fail for no reason. The reasons for the breakdown of the key should be sought by checking other components of the circuit - electrolytic capacitors, resistors and semiconductor elements of the primary circuit. The PWM chip is verified by replacing it with a known good one.
When using the Active Power Factor Correction (CMC) circuitry in the power module, the search for faulty elements is somewhat more complicated.
If the TOSHIBA 32AV501PR does not have an image, there is sound and the channels are switched, there is a possibility of a malfunction of the display backlight, or their power converter - inverter. Sometimes when you turn on the image appears and disappears immediately. In such cases, it is necessary to check the electrolytic capacitors of the power filter of the inverter itself, including in the secondary rectifier of the main PSU.
Often attempts to repair the inverter 75012525 are hampered by the fact that the fault diagnosis is complicated by the operation of its protection, which is designed to turn off the inverter in emergency conditions - when the lamps are depressurized, breaks or short circuits in high-voltage connections and other emergency situations. Lock protection to localize the defect is popular among repairmen.
In such cases, special care should be taken during diagnostics, and after completion of all repair work, it is necessary to restore the circuit and the inverter protection for further safe operation of the TV.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repair only to professionals with sufficient experience in the field of electronic equipment repair.


SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    Toshiba 32AV501PR Ver. 2.00 PE0484 PE0486 PE0531 PE0640 

 The appearance of MainBoard PE0484 is shown in the figure below:
PE0484
PE0484 can be used in TVs:
TOSHIBA 32AV500PR (Panel LC320WXN (SB)(B1)), TOSHIBA 32AV500PSR (Panel LC320WXN (SB)(B1)), TOSHIBA 32AV501PR (Panel LK315T3LA31), TOSHIBA 32AV502PR (Panel LK315T3LA31 (75012574)), TOSHIBA 37AV502PR (Panel LC370WXN(SA)(C2) 75012583), TOSHIBA 42AV500PSR (Panel LC420WXN (SA)(B1)), TOSHIBA 42AV501PR (Panel LC420WX7-SLC1), TOSHIBA 42AV502PR (Panel LC420WXN-SAB1), TOSHIBA 37AV500PR (Panel AX094B002B).
Main features of the TOSHIBA 32AV501PR device:
Installed matrix (LCD panel) LK315T3LA31.
To power the backlight, an inverter 75012525 is used.
The required supply voltage for all nodes of the TOSHIBA 32AV501PR TV provides a switching power supply.
MainBoard - the main board (motherboard) is a PE0484 module, using TDA8891H1 / N1B TDA15451HV / N1B00 chips and others.
The TAEA-G081D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: SHARP
Model: LK315T3LA31
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
Surface: Antiglare, Hard coating (3H)
Brightness: 450 cd / m²
Contrast Ratio: 2000: 1
Display Colors: 16.7M (8-bit)
Response Time: 7 (G to G)
Frequency: 60Hz
Lamp Type: 10 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V