Saturday, 15 February 2020

REPAIR / SERVICING TV LG 32LB76-ZD

Technical description and composition of the LG 32LB76-ZD TV, panel type and applicable modules. The composition of the modules.
LG
Model: 32LB76-ZD
Chassis / Version: L079C
Panel: LC320WX6 (SL) (A3)
T-CON: LC320WXN SAA1 6870C-0195A TPS65152 // LC320W01-SLB1-G31, 6870C-0320A
Inverter (backlight): LC320 6632L-0494A LGIT PNEL-T712A Rev-1.3
PWM Inverter: BD7877FS (32)
Power Supply (PSU): YP32DVR
PWM Power: ICE3B1565J (Standby), 5501A, 4428YM, U3037M
MainBoard: EAX37632202 - EBR39300502
IC MainBoard: FLi8548H-LF, 24LC25vv6vV320CTTC-7v825DC256160CEv2069Q, MSP4450K E8, STi5100GUC
Tuner: TDFC-G167P
Control: MKJ32022835, IR: EAX35731602
Specifications 32LB76
LG 32LB76-ZD
General recommendations for repairing TV LCD
Repair of an LG TV with the L079C chassis should begin with a fault diagnosis, which involves a careful inspection of the external and internal elements of the device. 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. In most cases, the repairman can guess the causes of the defect and possible consequences by the characteristic signs of typical TV defects, for example, ring cracks formed in the soldering of element leads, swollen rectifier filter capacitors, charred resistors and other circuit elements.
In the absence of any signs of operability, when the LG 32LB76-ZD does not turn on and does not signal anything with the control lights on the panel, there is a possibility of a malfunction of the TV's YP32DVR power module. With the same manifestations, the power regulator of the control processor on the motherboard may be faulty. When diagnosing and repairing the power supply, after replacing the swollen capacitors of the filters of the secondary rectifiers (if any), you must first check the mains fuse. When it is broken, the power elements of transistors and rectifier bridge diodes should be checked for avalanche (thermal) breakdown.
It should be borne in mind that in the practice of repair it is extremely rare that key transistors in switching power supplies (SMPS) fail for no reason that should be sought by checking other components, for example, a breakdown of the key can provoke faulty elements of the damper circuits, or dried electrolytic capacitors or dangling primary resistors BP circuits involved in the stabilization process. In this case, all semiconductor elements of the strapping of the ICE3B1565J PWM controller microcircuit (8) are subject to verification, which it is desirable to verify by replacement.
Sometimes the LG 32LB76-ZD TV does not have an image, but there is sound, or the image appears and immediately disappears. In this case, there is a high probability of a malfunction of the backlight converter, or of the lamps themselves, which can be checked by replacement. In such cases, it is necessary to verify the serviceability of all electrolytic capacitors of the filter according to the power supply of the inverter itself, including the power supply unit (power supply unit). When diagnosing a malfunction of the inverter with the protection off, special precautions must be taken, because there is a risk of failure of the power elements of the inverter. After the diagnosis, it is imperative to restore the protection circuits for the inverter to operate normally.
It is advisable to start repairing the 88EBR010 motherboard by diagnosing and checking all the linear stabilizers or power converters of its microcircuits. Sometimes it may be necessary to update the software (software) - flashing FLASH or EEPROM.
Attention to users! Self-repair of the LG 32LB76-ZD TV without the appropriate qualifications and experience can lead to its complete non-repairability!


SCHEMATIC MANUAL ------------------------->  LG 32LB75, 32LB75-ZB, 32LB76, 32LB76-ZD Chassis LD73C


 The appearance of the MainBoard EAX37632202 is shown in the figure below:
EAX37632202
EAX37632202 can be used in TVs:
LG 26LB75-ZE (Panel V260B1-L03 Rev. C3), LG 32LB76-ZD (Panel LC320WX6 (SL)(A3)), LG 32LB75 (Panel LC320WXN (SA)(A1)).
The appearance of the power supply
Main features of the device LG 32LB76-ZD:
Installed matrix (LCD panel) LC320WX6 (SL) (A3).
The matrix control uses the Timing Controller (T-CON) LC320WXN.
An LC320 inverter is used to power the backlight lamps; it is controlled by the BD7877FS PWM controller (32).
The necessary supply voltages for all nodes of the LG 32LB76-ZD TV are generated by the YP32DVR power module or its analogs using ICE3B1565J (Standby), 5501A, 4428YM, U3037M microcircuits.
MainBoard - the main board (motherboard) is an EAX37632202 module, using chips FLi8548H-LF, 24LC25vv6vV320CTTC-7v825DC256160CEv2069Q, MSP4450K E8, STi5100GUC and others.
The TDFC-G167P tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG.Philips LCD
Model: LC320WX6-SLA3
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 697.68x392.26 mm
Surface: Antiglare (Haze 13%), Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit)
Response Time: 8/10 (Tr / Td)
Frequency: 60Hz
Lamp Type: 14 pcs EEFL Without Driver
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V