LG LED
Model: 50LB650V
Chassis / Version: LB42B
Panel: LC500DUH (FG) (P1)
LED backlight: 6916L-1781A & 6916L-1782A
LED driver (backlight): integrated into PSU
PWM LED driver: BL0202B
MOSFET LED driver: AP9561
Power Supply (PSU): EAX65423801 2.1
PWM Power: MAP8800, FA6A01N, NR134S
MOSFET Power: K7A60W
MainBoard: EAX65384004 1.5 EBR78515108
IC MainBoard: CPU: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR
Tuner: TDJM-G101D
Specifications 50LB650V
LG 50LB650V
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The LG 50LB650V TV does not turn on, does not respond to the remote control and the control panel buttons, the indicators do not light or flash.
Failure in such cases should begin to be sought in the power supply circuit of the EAX65423801. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches (K7A60W) and rectifier diodes for a possible partial or complete breakdown.
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.
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 damper circuits, or negative feedback elements in the stabilization circuit. PWM controllers MAP8800, FA6A01N, NR134S, in the absence of visible damage or explicit short-circuit between the terminals, are checked by replacing with new ones, or obviously working.
- 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.
In such cases, the most likely malfunction of the LED backlight elements. 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, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the EAX65384004 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 must check the health of its elements - CPU: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR. 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 power supply to the TDJM-G101D tuner and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
TV users and owners need to remember that attempts to self-repair an LG 50LB650V TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
Service manual / schematic diagram ------------> LG 50LB650V Chassis LB42B
50LB6500, 50LB650V, 50LB653V
The appearance of the MainBoard EAX65384004 is shown in the figure below:
EAX65384004
EAX65384004 can be used in TVs:
LG 32LB650V ZE (Panel LC320DUH (FG)(P2)), LG 47LB650V ZE (Panel LC470DUH (FG) (P2)), LG 42LB650V (Panel LC420DUH (FG)(P2)), LG 42LB671V ZF (Panel LC420DUH (PG) (F1)), LG 47LB671V (Panel LC470DUH (PG)(F1)), LG 42LB653V ZK (Panel LC420DUH (FG)(P1)), LG 42LB720V (Panel LC420DUH (PG)(F1)), LG 42LB658V (Panel LC420DUH (FG)(P2)), LG 47LB677V (Panel LC470DUH (FG)(F1)), LG 42LB679V (Panel LC420DUH (PG)(F1)), LG 47LB653V (Panel LC470DUH (FG)(P1)), LG 32LB653V (Panel LC320DUH( FG)(P1)), LG 42LB690V (Panel LC420DUH (PG)(F1)), LG 55LB630V (Panel LC550DUH).
The appearance of the power supply
Main features of the device LG 50LB650V:
Installed matrix (LED-panel) LC500DUH (FG) (P1).
To power the backlight LEDs, a converter is used, combined with the power supply, controlled by the BL0202B PWM controller. As power elements of the LED driver, keys of the type AP9561 are used.
The necessary supply voltages for all nodes of the LG 50LB650V TV are generated by the EAX65423801 power module or its analogs using MAP8800, FA6A01N, NR134S microcircuits and K7A60W type power switches.
MainBoard - the main board (motherboard) is an EAX65384004 module, using CPU chips: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAIR and others.
The TDJM-G101D tuner provides television reception and channel tuning.