Technical description and composition of the LG 32LA644V TV, type of panel and applicable modules. The composition of the modules.LG LED
Model: 32LA644V ZA
Chassis / Version: LD33B
Panel: LC320EUN (SF) (F1)
LED backlight: Edge Rev. 0.2 1 6920L-0001C; 6922L-0059A
LED driver (backlight): KLS-E320SNAHF06 A REV0.2 6917L-0144A
PWM LED driver: BD9470EFV
MOSFET LED driver: FDD850N10L
Power Supply (PSU): EAX64907901 (2.4) 2013.04.03
PWM Power: FA5760N, NCP3170A, LM2903
MOSFET Power: 6N12013, K12A60W, MDD3754
MainBoard: EAX64797003 (1.2) 12.11.29 P.K.D 183x225
IC MainBoard: CPU: LGE2122, NAND: SAA36403538 VER. 3.20.33 H5TQ4G63AFR x2 H5TQ2G63AFR NTP7513
Tuner: TDSQ-G601D EBL61240503
Specifications 32LA644V
LG 32LA644V
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 32LA644V TV does not turn on and does not show any signs of operability at all. There is no reaction to the remote control and control buttons from the front panel.
Most likely in this case, the main switching power supply (IIPS) - EAX64907901 module will turn out to be faulty. It is necessary to measure its output voltages and, if they are absent, you should check the power switches (6N12013, K12A60W, MDD3754) and rectifier diodes of the converters for the probability of a short circuit.
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually work normally in emergency short circuit mode. There are no output voltages. And with a short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and less often the current sensor at the source of the key.
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, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
Often in such cases, there is no LED backlight. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
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 is 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 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). Sometimes it is necessary to check or replace (if necessary) the elements of the MainBoard - CPU: LGE2122, NAND: SAA36403538 VER. 3.20.33 H5TQ4G63AFR x2 H5TQ2G63AFR NTP7513. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
Before replacing the TDSQ-G601D EBL61240503 tuner, 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
It should be remembered! Attempts to self-repair the LG 32LA644V TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!
Service manual and schematic diagram ------------------------------> LG 32LA644V Chassis LD33B.
CHASSIS : LD33B; MODEL : 32LA644V, 32LA644V-ZA
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 32LA644V:
Installed matrix (LED-panel) LC320EUN (SF) (F1).
To power the backlight LEDs, the KLS-E320SNAHF06 LED driver is used, controlled by the BD9470EFV PWM controller. As the power elements of the LED driver, keys of the FDD850N10L type are used.
The necessary supply voltages for all nodes of the LG 32LA644V TV are generated by the EAX64907901 power module or its analogs using FA5760N, NCP3170A, LM2903 microchips and 6N12013, K12A60W, MDD3754 type 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 TDSQ-G601D EBL61240503 tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC320EUN-SFF1
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1920x1080, FHD
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 698.4x392.9 mm
Surface: Antiglare (Haze 1%), Hard coating (2H)
Brightness: 350 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 16.7M (8-bit), CIE1931 68%
Response Time: 8 (G to G)
Frequency: 60Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V