Monday 17 February 2020

REPAIR / SERVICING TV LG 32LF560U

Technical description and composition of the LG 32LF560U TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 32LF560U ZB
Chassis / Version: LD55T
Panel: NC320DXN VSBP5
LED driver (backlight): integrated into PSU; 119.7V 250mA
Power Supply (PSU): EAX66171501 (2.1) - LGP32D-15CH1
PWM Power: SSC3S111
MOSFET Power: MDF11N65B
MainBoard: EAX66203805 (1.2)
IC MainBoard: LGE2136, 25L8035E
Tuner: TDJM-G301D
Control: AKB74475403, IR Assy Ver 1.5
Specifications 32LF560U
LG 32LF560U
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The LG 32LF560U TV does not turn on. The control lights do not light or flash. On the remote control and other control buttons does not respond.
Often in such cases, the EAX66171501 power module is faulty. It is necessary to measure the output voltages in the secondary circuits, and in case of their absence, check the serviceability of the power switches of the converters and rectifier diodes for a short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during a short circuit in the power elements of the primary circuit, the mains fuse usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, power supply, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. PWM chip SSC3S111 can also cause a malfunction of the power switch of the converter and is checked by replacement.
- 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.
Often in such cases, there is no LED backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the LED line for breaks without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts will be required, and ideally, a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters, as a rule, light up a single 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as a health indicator. In faulty LEDs, the zener diode will either be cut off or broken into short-circuit.
- 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 EAX66203805 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). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the elements LGE2136, 25L8035E. BGA chip malfunctions are usually easy to detect by warming up.
If a TDJM-G301D tuner is suspected of malfunction, first of all, it is necessary to verify the correctness of the software, as well as the presence of the necessary supply voltage levels and data exchange pulses with the processor via the I2C bus at the corresponding tuner pins.
Attention to users! Self-repair of the LG 32LF560U TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!


Service manual and schematic diagram---------------------------->  LG 32LF560U Chassis LD55T.

MODS :  32LF56**, 32LF56**-Z*

 You can reduce the backlight current in TVs with LGP32D-15CH1 power supplies (EAX66171501) if you increase the resistance of the current sensor - the R816 resistor from 2.4 Ohm to 3 Ohm. Then the backlight current will proportionally decrease from 250 mA to 200 mA. If you install a 3.3 Ohm resistor, the current will decrease to 180 mA.

More details on this page


 The appearance of the MainBoard EAX66203805 is shown in the figure below:
EAX66203805
EAX66203805 can be used in TVs:
LG 32LF564U (Panel LC320DXE (MG)(A3)), LG 42LF550V (Panel LC420DUE (MG)(A6)), LG 32LF560U ZB (Panel NC320DXN VSBP5 ), LG 42LF560V (Panel LC420DUE (MG)(A3)), LG 32LF562V (Panel NC320DUN-VBBP3 (EAJ63171201)), LG 32LF564V (Panel NC320DUN VBBP3), LG 32LF560V (Panel NC320DUN-VBBP3), LG 49LF620V 49LF620V-ZB (Panel LC490DUE (MG)(P2)), LG 42LF551C (Panel LC420DUE-MGA6).
The appearance of the power supply
Main features of the device LG 32LF560U:
Installed matrix (LED-panel) NC320DXN VSBP5.
To power the backlight LEDs, a converter is used, combined with a power supply.
The necessary supply voltages for all nodes of the LG 32LF560U TV are generated by the EAX66171501 power module, or its analogs using SSC3S111 microcircuits and power switches of the MDF11N65B type.
MainBoard - the main board (motherboard) is an EAX66203805 module, using LGE2136, 25L8035E chips and others.
The TDJM-G301D tuner provides TV reception and channel tuning.