Monday 17 February 2020

REPAIR / SERVICING TV LG 32LF564V

Technical description and composition of the LG 32LF564V TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 32LF564V
Chassis / Version: LD55T
Panel: NC320DUN VBBP3
T-CON: HV320FHB-N00 47-6021049
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), RD5NH41F37 3.05.45
IC MainBoard: CPU: LGE2134; NAND Flash: TC58NVG0S3HTA00; SPI Flash: MX25L8035EM2I; EEPROM: 24C256
Tuner: TDJM-G301D
Control: IR: EBR78925202
Specifications 32LF564V
LG 32LF564V
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 32LF564V TV does not turn on at all. The control lights do not light or flash. The TV on the remote control and the control panel buttons do not respond.
Often in such cases, the EAX66171501 power module is faulty. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, check the serviceability of power switches (MDF11N65B) and rectifier diodes for possible breakdown (short circuit).
In case of any breakdowns in the secondary circuits, the converter can operate in emergency short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key more often breaks.
Mos-Fet power switches, used in switching power supplies, sometimes fail due to a malfunction of any other elements that can put it out of operation in key mode or create an excess of the maximum permissible parameters of the switch. These can be elements supplying the PWM controller, frequency-setting or damping circuits, or negative feedback elements in the stabilization circuit. PWM controllers SSC3S111, in the absence of visible damage or obvious short-circuit between the terminals, are checked by replacing with new, or obviously working.
- There is no image, there is sound, it responds to the remote control, the channels are switched. In some cases, the image appears when you turn on and immediately disappears.
A malfunction is usually most likely in these cases at the backlight nodes of the display matrix. 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 line of series-connected LEDs without a special current source, and for this purpose it is not safe to use any voltage sources above 12V for them. Then it remains only to open the panel and check each LED separately. Usually, Chinese 9V-powered multimeters light up a single 3-volt LED, if you connect the probes in the forward direction, the red probe to the anode, and the black to the cathode. In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as a health indicator. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- The indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
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). If it is not possible to replace the MB (SSB) card, you need to check the health of its elements - CPU: LGE2134; NAND Flash: TC58NVG0S3HTA00; SPI Flash: MX25L8035EM2I; EEPROM: 24C256. Defective components should be replaced.
If there is no reception of television channels, but the TV is working properly from external devices, first of all it is necessary to check the voltage of the TDJM-G301D tuner and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Attention! For users and owners of 32LF564V TVs who do not have the appropriate qualifications, knowledge and experience, we strongly recommend against attempting self-repair in order to avoid negative consequences that could lead to complete non-serviceability of the device.


Service manual and schematic diagram ----------------------->  LG 32LF564V Chassis LD55T. 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 32LF564V:
Installed matrix (LED-panel) NC320DUN VBBP3.
The matrix control uses the Timing Controller (T-CON) HV320FHB-N00.
To power the backlight LEDs, a converter is used, combined with a power supply.
The necessary supply voltages for all nodes of the LG 32LF564V TV are generated by the EAX66171501 power supply module or its analogs using SSC3S111 microcircuits and power switches of the MDF11N65B type.
MainBoard - the main board (motherboard) is an EAX66203805 module, using CPU chips: LGE2134; NAND Flash: TC58NVG0S3HTA00; SPI Flash: MX25L8035EM2I; EEPROM: 24C256 and others.
The TDJM-G301D tuner provides TV reception and channel tuning.