Saturday 15 February 2020

REPAIR / SERVICING TV LG 32LA662V

Technical description and composition of the LG 32LA662V TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 32LA662V
Chassis / Version: LD33B
Panel: LC320EUB (PF) (P1)
LED backlight: 6922L-0074A
T-CON: 6922L-0074A
LED driver (backlight): 6917L-0132A PPW-LE32TM-O (A) REV0.5
PWM LED driver: BD9470EFV
MOSFET LED driver: SDB5150D
Power Supply (PSU): EAX64907901 2.4
PWM Power: FA5760N, NCP3170A, LM2903
MOSFET Power: 13NM60N, 10NM60N
MainBoard: EAX64797003 EBR76823172
IC MainBoard: CPU: LGE2122, NAND: SAA36403538, H5TQ4G63AFR, H5TQ2G63AFR, NTP7513
Tuner: TSQ-G601D (B) EBL61240503
Specifications 32LA662V
LG 32LA662V
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 32LA662V 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.
In such cases, the EAX64907901 power supply is usually faulty. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, check the serviceability of the power switches (13NM60N, 10NM60N) and rectifier diodes for possible breakdown (short circuit).
In case of diode breakdowns in the secondary circuits, the converter can operate in emergency short-circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key 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. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM) FA5760N, NCP3170A, LM2903, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- 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.
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.
To detect a break in the LED lines without disassembling the panel, a current source is required. It is impossible to open transitions connected in series with a simple multimeter; voltage of several tens of volts is necessary.
- The TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly 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). Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Checking or replacing CPU elements: LGE2122, NAND: SAA36403538, H5TQ4G63AFR, H5TQ2G63AFR, NTP7513 requires the necessary training and professional skills to repair modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by warming up.
Before replacing the tuner TSQ-G601D (B) EBL61240503, if there is no tuning for the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus
Owners and users of the LG 32LA662V TV should remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!


Service manual and schematic diagram ------------------->  LG 32LA662V Chassis LD33B

 To reduce the backlight current in LED drivers with a BD9470EFV controller (TSSOP-B28), it is necessary to proportionally increase the total resistance of the resistors from pin 8 (ISET) to the chassis. The resistance Rset (in kilo-ohms) is selected from the ratio 3000 / Iled, where Iled is the maximum current in each of the six channels in milliamps.

More details on this page



 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 32LA662V:
Installed matrix (LED-panel) LC320EUB (PF) (P1).
The matrix control uses the Timing Controller (T-CON) 6922L-0074A.
To power the backlight LEDs, the 6917L-0132A LED driver is used, controlled by the BD9470EFV PWM controller. As power elements of the LED driver, keys of the SDB5150D type are used.
The necessary supply voltages for all nodes of the LG 32LA662V TV are generated by the EAX64907901 power supply module or its analogs using FA5760N, NCP3170A, LM2903 microchips and 13NM60N, 10NM60N power switches.
MainBoard - the main board (motherboard) is an EAX64797003 module using CPU chips: LGE2122, NAND: SAA36403538, H5TQ4G63AFR, H5TQ2G63AFR, NTP7513 and others.
The tuner TSQ-G601D (B) EBL61240503 provides the reception of television programs and tuning to channels.