Thursday 20 February 2020

REPAIR / SERVICING TV LG 32LS350T

Technical description and composition of the LG 32LS350T TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 32LS350T ZA
Chassis / Version: LD21C
Panel: T320XVN01.1
LED backlight: 73.32T21.002-2-JS1
T-CON: T315XW02 V2 TEST BD
LED driver (backlight): T315XW02 V2 TEST BD
PWM LED driver: L302-1F
Power Supply (PSU): EAX64324701 (1.5) - LGP32L-12P - P / N: EAY62512301
PWM Power: FSL106HR (Standby DIP-8)
MainBoard: EAX64910001 (1.0)
IC MainBoard: CPU: LGE2111A-T8, Nand: H27U1G8F2BTR, DDR: K4B1G1646G-BCK0
Tuner: TDSN-G301D
Control: IR: EBR74986702 LM35-55
Specifications 32LS350T
LG 32LS350T
General repair guidelines for TV LCD LED
In the absence of any signs of operability, when the LG 32LS350T does not turn on and does not signal anything with the control lights on the panel, there is a possibility of a malfunction of the power module LGP32L-12P EAX64324701 (1.5) P / N: EAY62512301 TV. First of all, it is necessary to replace the swollen capacitors of the rectifier filters, if any. If the mains fuse is cut off in the power supply, in most cases a breakdown of the power key (s) is detected, which can be integrated with the PWM controller, or a separate field-effect transistor can be used. The rectifier bridge diodes and the electrolytic capacitor of the mains rectifier filter should also be checked.
Power switches in switching power supplies (SMPS) fail extremely rarely for no reason and, if they are broken, it is necessary to look for a malfunction in the stabilization circuits by checking electrolytic capacitors, semiconductor devices, and resistors in the primary circuit. The cause may be a malfunction of the FSL106HR PWM controller chip, which can only be checked by replacing it with a new or obviously working one.
If the LG 32LS350T has no image, but there is sound and the TV is controlled by the remote control, a malfunction in the backlight circuits of the T320XVN01.1 panel is likely. LEDs or their power converter - LED driver may be faulty. Often in such cases, when you turn on the TV, an image appears and immediately disappears. First of all, it is necessary to verify the operability of the electrolytic capacitors of the rectifier filter supplying the backlight assembly.
The lack of backlight often occurs due to an open circuit in the LED circuit. There is a need for disassembling the panel and checking the LEDs themselves, as well as the same contact connections in the connectors and rations of the terminals.
To check the health in the LED circuit, it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED individually with a simple Chinese multimeter (powered by 9 volts) in the P-N-junction test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. A zener diode PN junction indirectly indicates a LED-a
On the EAX64910001 (1.0) motherboard, in case of a malfunction, you should first check the performance of all the stabilizers and power converters of the microcircuits, and also, if necessary, update the software (software).
When repairing an MB board, you need to check its CPU components: LGE2111A-T8, Nand: H27U1G8F2BTR, DDR: K4B1G1646G-BCK0. Defective items should be replaced. If BGA chips are installed, their malfunction is usually localized by heating.
If the TV works normally from external devices, but does not tune into television channels, the TDSN-G301D tuner may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Attention to users! Self-repair of the LG 32LS350T TV without the appropriate qualifications and experience can lead to its complete non-repairability!


SCHEMATIC ------------------------->  LG 32LS3500/350S/350T/3510, 32LS3590/359S/359T, 32LS3500/350S/350T-ZA 32LS3510-ZB, 32LS3590/359S/359T-ZC Chassis LD21C.


SCHEMATIC OF PSU ---------------------------->  LGP32L-12P EAY62512301 EAX64324701 Power supply


 The appearance of the MainBoard EAX64910001 is shown in the figure below:
EAX64910001
EAX64910001 can be used in TVs:
LG 32LS340T (Panel LC320DXN), LG 32LS3510-ZB (Panel LC320EXN SEA2), LG 42CS460 (Panel LC420WUE (SC)(A3)), LG 32LS350T ZA (Panel T320XVN01.1), LG 42LS345T (Panel HC420DUN-SLCP1 11XX), LG 32CS465 ZA (Panel LC320WXN (SC)(A4)), LG 32LS345T (Panel 331537561 KENMOS 1365X768).
The appearance of the power supply
Main features of the device LG 32LS350T:
Installed matrix (LED panel) T320XVN01.1.
The matrix control uses the Timing Controller (T-CON) T315XW02.
The LED driver T315XW02 is used to power the backlight LEDs, it is controlled by the L302-1F PWM controller.
The necessary supply voltages for all nodes of the LG 32LS350T TV are generated by the EAX64324701 power module or its analogs using FSL106HR (Standby DIP-8) microcircuits.
MainBoard - the main board (motherboard) is an EAX64910001 module using CPU chips: LGE2111A-T8, Nand: H27U1G8F2BTR, DDR: K4B1G1646G-BCK0 and others.
The TDSN-G301D tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: T320XVN01.1
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: AMVA, Normally Black, Transmissive
Active Area: 697.685x392.256 mm
Surface: Antiglare (Haze 2%), Hard coating (3H)
Brightness: 300 cd / m²
Contrast Ratio: 2000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 6.5 (G to G)
Frequency: 60Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V