Technical description and composition of the LG 20LC1R TV, panel type and applicable modules. The composition of the modules.LG
Model: 20LC1R 20LC1R-ZG
Chassis / Version: CL-81
Panel: LC201V02 (SD) (A1)
Lamp backlight: 6 Lamp CCFL
T-CON: 6870S-0309A
Inverter (backlight): integrated into PSU
PWM Inverter: BIT3105P
Power Supply (PSU): 6870TB68D11 - YPLM-M004B REV 1.0
PWM Power: ICE3BS02
MOSFET Power: 04N60C3
MainBoard: CL-81 68709M0005H
IC MainBoard: TDA15521E / N1F80, 24C32, SST39VF020
Tuner: TAEW-G053D
Control: IR: 68709S0112D
Specifications 20LC1R
LG 20LC1R
General recommendations for repairing TV LCD
Possible malfunctions
- The LG 20LC1R TV does not turn on and does not show any signs of operability at all. There is no reaction to the remote control and control buttons from the front panel.
In such cases, the fault should be sought first in the 6870TB68D11 power supply module. It is then necessary to measure its output voltages and, if they are absent, you should check the power switches (04N60C3) and the rectifier diodes of the converters for a short circuit probability.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in emergency short-circuit mode without output voltages, and during short circuit in the elements of the primary circuit, the main fuse and, less often, the current sensor at the source of the key are most often cut off.
Breakdown of power switches (MosFet) in pulsed sources is sometimes caused by malfunctions of other circuit elements, for example, in circuits supplying a PWM controller, frequency-setting or damper ones, as well as in negative feedback (OOS) stabilization circuits. PWM controllers (PWM) ICE3BS02, if they do not have visible damage to the chassis and open fault between the terminals, are usually checked by replacement.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
The defect can be caused by problems in the nodes or elements of the backlight of the display, or in the power supply of the lamps or the inverter.After checking all the electrolytic capacitors of the filters that are involved in the power supply to the inverter, you must ring in its converter power keys for breakdown and secondary windings of transformers for an open.
Sometimes, for diagnostic purposes, it is necessary to disable the inverter protection. In such cases, special care must be taken during work, and the protection circuits should be restored immediately after the repair is completed.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the CL-81 motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). Sometimes it is necessary to check or replace (if necessary) the elements of the MainBoard board - TDA15521E / N1F80, 24C32, SST39VF020. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
Before changing the tuner TAEW-G053D, if there is no possibility of tuning to television channels, you should make sure that there are supply voltages that must be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Attention TV owners! Attempts at self-repair of LG 20LC1R are not recommended by the manufacturer and can lead to serious negative consequences!
Service manual and schematic diagram -------------------> LG 20LC1R Chassis CL-81.
FIRMWARE SPI FLASH, EEPROM ----> LG 20LC1R 20LC1R-ZG CL-81, Main: CL-81, Panel: LC201V02-A3KA
The appearance of the MainBoard CL-81 is shown in the figure below:CL-81
The appearance of the power supply
Main features of the device LG 20LC1R:
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 20LC1R TV are generated by the power supply module 6870TB68D11, or its analogs using ICE3BS02 microcircuits and power switches type 04N60C3.
MainBoard - the main board (motherboard) is a CL-81 module, using TDA15521E / N1F80, 24C32, SST39VF020 chips, and others.
The TAEW-G053D 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