Friday, 28 February 2020

REPAIR / SERVICING TV LG 42LN613V

Technical description and composition of the LG 42LN613V TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 42LN613V
Chassis / Version: LD33B
Panel: LC420DUE (SF) (R4)
LED backlight: 6916L-1412A, 6916L-1414A, 6916L-1413A, 6916L-1415A
T-CON: 6870C-0452A LC500DUE-SFR
LED driver (backlight): integrated into PSU
PWM LED driver: BD9483F
Power Supply (PSU): EAX64905401 (1.5) LGP42-13R2
PWM Power: SSC9527S (PWM Resonant), R2A20133D (PFC), 3BR4765JZ (Standby)
MainBoard: EAX64797003 (1.2) EBR76823170
IC MainBoard: CPU: LGE2122, NAND: SAA36403538 VER. 3.20.33 H5TQ4G63AFR x2 H5TQ2G63AFR NTP7513
Tuner: TSQ-G601D (B)
Specifications 42LN613V
LG 42LN613V
General repair guidelines for TV LCD LED
Possible malfunctions
- LG 42LN613V does not turn on and does not show any signs of performance at all. Does not blink indicators and does not respond to control buttons.
In such cases, the malfunction should be sought first in the EAX64905401 power supply module. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches and rectifier diodes for a possible partial or complete breakdown.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during a short circuit in the 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, 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) SSC9527S (PWM Resonant), R2A20133D (PFC), 3BR4765JZ (Standby) are usually checked by replacing with new ones, or obviously working.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
The most likely in these cases is a malfunction of the 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 indicator blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the EAX64797003 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 some cases, to repair the MB board (SSB), it may be necessary to replace the chips - CPU: LGE2122, NAND: SAA36403538 VER. 3.20.33 H5TQ4G63AFR x2 H5TQ2G63AFR NTP7513 for new or obviously working. In cases where BGA technologies are used, defects are usually localized by the heating method.
If a TSQ-G601D (B) 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 required voltage levels and the data exchange pulses with the processor via the I2C bus on the corresponding tuner pins.
Attention to users! Self-repair of the LG 42LN613V TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!



 SCHEMATIC DIAGRAM ---------->  LG 42LN613X, 42LN6138, 42LN613S, 42LN613V - Chassis LD33B.

  SCHEMATIC DIAGRAM ---------->  EAX64905401 LGP42-13R2 Power Supply schematic diagram

 You can limit the backlight current in TVs with LGP42-13R2 power supplies (EAX64905401) by increasing the resistance of the current sensors R811-R818 - channel 1 and R829-R836 - channel 2. All resistors are in pairs of 4.3 Ohm. To reduce the backlight current by 25%, one pair of resistors in each channel should be removed.


 The appearance of the MainBoard EAX64797003 is shown in the figure below:
EAX64797003
EAX64797003 can be used in TVs:
LG 42LA620V (Panel LC420DUE (SF)(U1)), LG 32LN570V (Panel LC320DUE (SF)(R1)), LG 50LA644V (Panel LC500EUN (SF)(F1)), LG 47LA660V (Panel LC470EUG (PF)(F1)), LG 47LA621V (Panel LC470DUE (SF)(U1)), LG 42LA644V (Panel LC420EUN (SF)(F2)), LG 39LA620V ZA (Panel T390HVJ01.0), LG 42LA621V ZD (Panel LC420DUE (SF)(U1)), LG 32LA621V ZD (Panel LC320DUE (SF)(U1)), LG 32LN655V (Panel LC320EUB (PF)(M1)), LG 42LA667V (Panel LC420EUH (PF)(P1) ), LG 47LN613V (Panel LC470DUE (SF)(R4)), LG 32LA667V ZB (Panel LC320EUB (PF)(P1)), LG 55LA660V ZA (Panel LC550EUH (PF)(P1)), LG 47LA620V ZA (Panel LC470DUE (SF)(U1)), LG 32LN613V ZB (Panel LC320DUE (SF)(R4)), LG 42LN655V ZB.BRUZLJU (Panel LC420EUH (PF)(M1)), LG 32LA644V ZA (Panel LC320EUN (SF)(F1)), LG 42LN613V (Panel LC420DUE (SF)(R4)), LG 47LA690V ZB (Panel LC47EUH (PF)(P1)), LG 47LA662V (Panel LC470EUG (PF)(F1)), LG 42LA645V 42LA645V-ZC.BRUYLJU (Panel LC420EUN (SF)(F3)), LG 32LA660V (Panel LC320EUB (PF)(P1)), LG 47LA644V 47LA644V-ZA (Panel LC470EUN (SF)(F2)), LG 50LA667S (Panel T500HVD02.1), LG 47LA691V (Panel LC470EUH (PF)(P1)), LG 32LA662V (Panel LC320EUB (PF)(P1)).
The appearance of the power supply
Main features of the device LG 42LN613V:
Installed matrix (LED-panel) LC420DUE (SF) (R4).
The matrix control uses the Timing Controller (T-CON) 6870C-0452A.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by the BD9483F PWM controller.
The necessary supply voltages for all nodes of the LG 42LN613V TV are generated by the EAX64905401 power module, or its analogs using SSC9527S (PWM Resonant), R2A20133D (PFC), 3BR4765JZ (Standby) microcircuits.
MainBoard - the main board (motherboard) is an EAX64797003 module using CPU chips: LGE2122, NAND: SAA36403538 VER. 3.20.33 H5TQ4G63AFR x2 H5TQ2G63AFR NTP7513 and others.
The TSQ-G601D (B) tuner allows you to receive television programs and tune to channels.