Saturday 11 April 2020

REPAIR / SERVICING TV DAEWOO LT32L2

Technical description and composition of the DAEWOO LT32L2 TV, type of panel and applicable modules. The composition of the modules.
DAEWOO
Model: LT32L2
Chassis / Version: SL-S00T / S10T
Panel: LTA320AB02
T-CON: 320AB02CP2LV0.3
Inverter (backlight): INVFT320A REV1.0
PWM Inverter: BD9882F
MOSFET Inverter: AP4525GEH
Trans Inverter: IT-133-06AA
Power Supply (PSU): FEL-3237VN
MainBoard: SL-S00T / S10T (V95)
IC MainBoard: CPU: STi1012BUA;
Tuner: TDFV-T131D
Control: R-60B01
Appearance
DAEWOO LT32L2
General recommendations for repairing TV LCD
Repair and diagnostics of any electronic device, in particular DAEWOO LT32L2, it is advisable to start with a careful external examination of internal and external elements. Often, by the external signs and nature of the damage to the elements, it becomes possible to draw some conclusions and determine a further algorithm for finding a defect before making the necessary measurements at control points. Swollen electrolytic or cermet capacitors, carbonized resistors, ring cracks in the soldering of the outputs of the elements - all this can significantly help the master to determine the causes and consequences of the malfunction of the TV.
If the LT32L2 TV does not turn on, does not make any sounds when it is turned on, and also no indicators on the front panel light or blink - there is a high probability of a malfunction in the power supply module. In some cases, there may be a malfunction only in standby power. Diagnostics and repair of the common power supply should always begin with a check of the mains fuse and the condition of the electrolytic capacitors of the secondary rectifier filters. Defective and swollen capacitors should be replaced with new ones. If the fuse breaks, it is advisable to check for a breakdown, first of all, all the power semiconductor elements of the converter and the diode bridge of the rectifier network, as well as the large electrolytic capacitor of the filter of the rectifier network.
A breakdown of the power switch of the pulse converter is often triggered by other elements, for example, in the stabilization or control circuits of this switch, as well as by the damper elements in its drain and TPI winding.
If the DAEWOO LT32L2 does not have an image, but there is sound, there is a possibility of a malfunction of the backlight or power converter. You should also make sure that the electrolytic capacitors of the secondary rectifiers of the common power supply are working. Turning off the protection for diagnostic purposes, it must be remembered that in this case there is a risk of failure of the power elements of the inverter. Upon completion of the diagnosis, all regular protection circuits should be restored.
The SL-S00T / S10T (V95) motherboard must be checked if there is no reaction to the remote control and function buttons, the standby indicator blinks or lights up continuously. In such cases, if the converters or power regulators of the microcircuit are working, a software update may be necessary.
The TDFV-T131D tuner malfunction 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.
Attention! For users and owners of LT32L2 TVs who do not have the appropriate qualifications, knowledge and experience, we strongly recommend against attempting self-repair in order to avoid negative consequences that could lead to complete non-repairability of the device.

Repair MainBoard
The appearance of the MainBoard SL-S00T is shown in the figure below:
SL-S00T
The appearance of the power supply
Main features of the DAEWOO LT32L2 device:
Installed matrix (LCD-panel) LTA320AB02.
The matrix control uses the Timing Controller (T-CON) 320AB02CP2LV0.3.
The INVFT320A inverter is used to power the backlight, it is controlled by the BD9882F PWM controller. The transformer IT-133-06AA is installed in the inverter converter. As power elements of the inverter, keys of the AP4525GEH type are used.
The formation of the necessary supply voltages for all nodes of the DAEWOO LT32L2 TV is carried out by the FEL-3237VN power module, or its analogs.
MainBoard - the main board (motherboard) is a SL-S00T module using CPU chips: STi1012BUA; and others.
The TDFV-T131D tuner provides television reception and channel tuning.
Information from an alternative source:
DAEWOO LT32L2 Chassis SL-S00T / S10T
Panel Type (Matrix): LTA320AB02
Motherboard: S / N: 4859818393-00A SL-S00T / S10T (V95), STi1012BUA, Tuner: TDFV-T131D
T-con: 320AB02CP2LV0.3
Invertor: INVFT320A REV1.0
PSU: FEL-3237VN
Remote control: R-60B01
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTA320AB02-W03
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: S-PVA, Normally Black, Transmissive
Active Area: 697.685x392.256 mm
Surface: Antiglare (Haze 14%), Hard coating (3H)
Brightness: 450 cd / m²
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 8 (G to G)
Frequency: 60Hz
Lamp Type: 12 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 41 pins
Voltage: 12.0V