Technical description and composition of the LG 42LN655V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 42LN655V ZB.BRUZLJU
Chassis / Version: LD33B / LC33B / LE33B
Panel: LC420EUH (PF) (M1)
LED backlight: 6922L-0072A
LED driver (backlight): integrated into PSU; 67.2V, 0.9A
PWM LED driver: R5F100BCAFP, IW7011
MOSFET LED driver: TK15A20D
Power Supply (PSU): EAX64905701 (2.5)
PWM Power: SSC9527S (PWM Resonant), R2A20133D (PFC), ICE3BR4765JZ (Standby)
MOSFET Power: 13NM60N, 10NM60N
MainBoard: EAX64797003 (1.2) EBR76823181
IC MainBoard: CPU: LGE2122, NAND: SAA36403538 VER. 3.20.33 H5TQ4G63AFR x2 H5TQ2G63AFR NTP7513
Tuner: TSQ-G601D (B) EBL61240503
Control: WIFI: TWFM-B006D
Specifications 42LN655V
LG 42LN655V
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 42LN655V TV does not turn on and does not show any sign of turning on at all. There are no reactions to the control buttons or the remote control.
In most of these cases, the EAX64905701 main switching power supply fails. It is necessary to measure its secondary output voltages, and in case of their absence, check the serviceability of the power switches (13NM60N, 10NM60N) of the converters and rectifier diodes for a possible short circuit.
In case of breakdowns of power elements in the secondary circuits, the converter can operate in a short circuit mode, and during short circuit in the elements of the primary circuit, the mains fuse usually breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. It can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power key can be PWM (PWM) SSC9527S (PWM Resonant), R2A20133D (PFC), ICE3BR4765JZ (Standby). It is checked only by replacement with a known good one.
- There is no image, there is sound, it responds to the remote. 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.
When diagnosing, it is necessary to take into account that it is impossible to check the open in the chain of LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally, a current source. By opening the panel, each LED can be checked separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect probes in the forward direction to it. In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of health. In the event of a LED malfunction, its 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 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). When repairing an MB board, you need to check its CPU components: LGE2122, NAND: SAA36403538 VER. 3.20.33 H5TQ4G63AFR x2 H5TQ2G63AFR NTP7513. Defective items should be replaced. If chips with BGA soldering technology are used, a problem in its implementation is detected by the local heating of the chip.
Before changing the tuner TSQ-G601D (B) EBL61240503, if it is not possible to tune to television channels, make sure that there are supply voltages that need to be measured on the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
We recommend the owners of the 42LN655V TV for repair only to qualified specialists with the necessary work experience! Self-repair attempts without the appropriate knowledge and skills can lead to irreversible negative consequences!
SCHEMATIC DIAGRAM ----------> LG 42LN655V Chassis LD33B/LC33B/LE33B.
PSU SCHEMATIC DIAGRAM ----------> EAX64905701 (2.5) LGP4247-13LPB
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 42LN655V:
Installed matrix (LED-panel) LC420EUH (PF) (M1).
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by a PWM controller R5F100BCAFP, IW7011. As the power elements of the LED driver, keys of the TK15A20D type are used.
The necessary supply voltages for all nodes of the LG 42LN655V TV are generated by the EAX64905701 power supply module or its analogs using SSC9527S (PWM Resonant), R2A20133D (PFC), ICE3BR4765JZ (Standby) microcircuits, and 13NM60N, 10NM60N power switches.
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 tuner TSQ-G601D (B) EBL61240503 provides the reception of television programs and tuned to channels.