Wednesday 19 February 2020

REPAIR / SERVICING TV LG 32LK455

Technical description and composition of the LG 32LK455 TV, panel type and applicable modules. The composition of the modules.
LG
Model: 32LK455 32LK455C
Chassis / Version: LC320WUN (SC) (A2)
Panel: EAX64272803
Lamp backlight: EEFL
T-CON: 6870C-0318B
Inverter (backlight): 6632L-0636A 3PEGA20003A-R
PWM Inverter: OZ9966SN, BA10324
Power Supply (PSU): EAX63985401 LGP32-11P
PWM Power: L6599AD (PWM Resonant), 3BR4765JZ (Stb)
MOSFET Power: MDF6N60
Mainboard: EAX64272803
IC MainBoard: LGE2111-T8, 24C08K, 25Q80BVSIG, NTP-7400L, AP7173 H5TQ1G63DFR, LCX244F204, AP2191D, AS324M-E1, MAX3232C
Tuner: TDSS-G101D p / n: EBL61060001
Control: IR: YWANN91301A LW4500 / LV2500 / LK550
Specifications 32LK455C
LG 32LK455
General recommendations for repairing TV LCD
Possible malfunctions
- The LG 32LK455 TV does not turn on and does not show any signs of turning on, does not respond to the control buttons or to the remote control.
With such manifestations, in some cases, the EAX63985401 power module is faulty. It is necessary to measure its output supply voltages, and in case of their absence, check the serviceability of the power switches (MDF6N60) of the converters and rectifier diodes for the probability of breakdown in PN semiconductor junctions.
In the event of breakdowns in the secondary circuits of the converter, it can usually fail in short circuit mode, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse or current sensor at the source of the key most often breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM circuits (PWM) L6599AD (PWM Resonant), 3BR4765JZ (Stb) are usually checked by replacing with new ones, or obviously working.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
These manifestations can be triggered by a power module, or by defects in the inverter, as well as a distortion of the currents in the lamps due to their uneven wear. If all the electrolytic capacitors of the filter according to the inverter power supply are serviceable, you should make sure that the lamps are in good working condition, then you need to check the converter keys and the secondary windings of the transformers.
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 enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
Repair or diagnostics of the EAX64272803 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). In cases of complex repairs of MB (SSB) and with the necessary skills and equipment, sometimes it may be necessary to replace its chips LGE2111-T8, 24C08K, 25Q80BVSIG, NTP-7400L, AP7173 H5TQ1G63DFR, LCX244F204, AP2191D, AS324M-E1, MAX3232C and other possible components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
Before replacing the TDSS-G101D p / n tuner: EBL61060001, if there is no tuning for the channels, first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus
Owners and users of the LG 32LK455 TV should remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!



The appearance of the MainBoard EAX64272803 is shown in the figure below:
EAX64272803
EAX64272803 can be used in TVs:
LG 42LK450-TG (Panel V420H2-L05), LG 32LK430 ZG (Panel LC320WUN (SC)(A2)), LG 42LK430 (Panel LC420WUE (SC)(A2)), LG 42CS560 ZD (Panel LC420WUE (SC)(A3)), LG 32LV3400 ZG (Panel LC320EUN (SD)(V2)), LG 32CS560 (Panel LC320WUN (SC)(A2)), LG 32LK455 32LK455C (Panel EAX64272803).
The appearance of the power supply
Main features of the device LG 32LK455:
Installed matrix (LCD-panel) EAX64272803.
The matrix control uses the Timing Controller (T-CON) 6870C-0318B.
To power the backlight, an inverter 6632L-0636A is used, it is controlled by the PWM controller OZ9966SN, BA10324.
The necessary supply voltages for all nodes of the LG 32LK455 TV are generated by the EAX63985401 power module or its analogs using L6599AD (PWM Resonant), 3BR4765JZ (Stb) microcircuits and MDF6N60 type power switches.
MainBoard - the main board (motherboard) is an EAX64272803 module, using chips LGE2111-T8, 24C08K, 25Q80BVSIG, NTP-7400L, AP7173 H5TQ1G63DFR, LCX244F204, AP2191D, AS324M-E1, MAX3232C and others.
Tuner TDSS-G101D p / n: EBL61060001 provides the reception of television programs and tuned to channels.