Technical description and composition of the LG 20LS1R TV, panel type and applicable modules. The composition of the modules.LG
Model: 20LS1R 20LS1R-ZG
Chassis / Version: CL-81
Panel: LC201V02 (SD) (A1)
T-CON: 6870S-0309A
Inverter (backlight): integrated in PSU
PWM Inverter: BIT3105P
Power Supply (PSU): YPLM-M004 - 6870TB68D11 - 2300KPG055A-F // AIVP-0032
PWM Power: ISE3BS02
MOSFET Power: 04N60C3
MainBoard: EAX31483003 (0) - EBR31752301
IC MainBoard: LGE9655-LF, KH25V4005A, 24C64
Tuner: TAFT-W005D
Control: 6710T00008B, IR: EAX31560402 (0)
Specifications 20LS1R
LG 20LS1R
General recommendations for repairing TV LCD
Repair of electronic equipment usually begins with its external inspection and diagnosis of the malfunction. In this case, you should examine all the internal components of the LG 20LS1R TV, as well as the external elements of the housing. Based on visible external changes in the state of the components, it is often possible to determine the direction of the troubleshooting before making the necessary measurements. If charred resistors, swollen electrolytic or cermet capacitors, ring cracks in the soldered terminals of transformers or heating elements are detected, it is advisable to establish the causes and consequences of the malfunction that has arisen, as well as to check the connected elements and assemblies.
Sometimes the LG 20LS1R TV just does not turn on. No control lights on the front panel are lit or blinking, the TV does not respond to the remote control and does not make any sounds or any signs of life when turned on. The most probable cause of the malfunction is the failure of the general power supply module YPLM-M004 - 6870TB68D11 - 2300KPG055A-F // AIVP-0032. If it is working properly, you must check the standby batteries on the Main Board. 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.
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 ISE3BS02 PWM controller microcircuit are subject to verification, which it is desirable to verify by replacement.
If the LG 20LS1R 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. When disabling protection in order to enable the diagnosis of a malfunction, special care should be taken, 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.
Repair of the motherboard EAX31483003 (0) - EBR31752301 must begin with the diagnosis and verification of all linear stabilizers and power converters of its microcircuits. Sometimes it may be necessary to update the software (software) - flashing FLASH or EEPROM. In some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - LGE9655-LF, KH25V4005A, 24C64 with new or obviously good ones. In cases where BGA technologies are used, defects are usually localized by the heating method.
The malfunction of the TAFT-W005D 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.
It is necessary to remember to users that attempts to self-repair a LG 20LS1R TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
Service manual and schematic diagram ----------------------> LG 20LS1R Chassis CL-81
The appearance of the MainBoard EAX31483003 is shown in the figure below:EAX31483003
The appearance of the power supply
Main features of the device LG 20LS1R:
Installed matrix (LCD panel) LC201V02 (SD) (A1).
The matrix control uses the Timing Controller (T-CON) 6870S-0309A.
To power the backlight, a converter is used, combined with a power supply, controlled by a BIT3105P PWM controller.
The necessary supply voltages for all nodes of the LG 20LS1R TV are generated by the YPLM-M004 power supply module or its analogs using ISE3BS02 microcircuits and power switches of the 04N60C3 type.
MainBoard - the main board (motherboard) is an EAX31483003 module, using LGE9655-LF, KH25V4005A, 24C64 and other chips.
The TAFT-W005D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG.Philips LCD
Model: LC201V02-SDA1
Type: a-Si TFT-LCD, Panel
Diagonal size: 20.1 inch
Resolution: 640x480, VGA
Display Mode: IPS, Normally Black, Transmissive
Active Area: 408x306 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 450 cd / m²
Contrast Ratio: 800: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 12/13 (Tr / Td)
Frequency: 60Hz
Lamp Type: 6 pcs CCFL Without Driver
Signal Interface: CMOS (1 ch, 8-bit), 41 pins
Voltage: 12.0V