Sunday 16 February 2020

REPAIR / SERVICING TV LG 32LD321

Technical description and composition of the LG 32LD321 TV, panel type and applicable modules. The composition of the modules.
LG
Model: 32LD321 32LD321-ZB
Chassis / Version: LD91A
Panel: T315XW03 V1
Inverter (backlight): VIT71884.00
PWM Inverter: OZ964SN
Power Supply (PSU): EAX62106801 - EAY61209901 - LGP32-10P1
PWM Power: L6599D, HS01G (PFC), ICE3B0365J (Standby)
MOSFET Power: K5A60D, K13A60D
MainBoard: EAX60686904 EBU60710856
IC MainBoard: CPU: LGE3368A (Saturn-6); NAND Flash: HY27US08121B-TPCB; SPI Flash: W25X32VSSIG; SOUND: NTP3100
Tuner: TDFW-G235D
Appearance
LG 32LD321
General recommendations for repairing TV LCD
Possible manifestations of defects
- LG 32LD321 TV does not turn on at all. There is no reaction to the remote control and control buttons from the front panel. Indicator lights do not light or flash.
With such manifestations, the EAX62106801 power supply module usually fails. It is necessary to measure its output voltages, and in case of their absence (full or partial), it is necessary to check the serviceability of power switches (K5A60D, K13A60D) of converters and rectifier diodes for the presence of a possible short circuit.
In case of any breakdowns in the secondary circuits, the converter can operate in emergency short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key more often 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) L6599D, HS01G (PFC), ICE3B0365J (Standby) are usually checked by replacing with new ones, or obviously working.
- There is no image, but there is sound and reaction to commands from the remote control. Or the image appears immediately after turning on and disappears.
These manifestations can be triggered by the power module, or by inverter defects, as well as by the distortion of the currents in the lamps due to their uneven wear. If all the electrolytic capacitors of the filter according to the inverter power supply are serviceable, you should make sure that the lamps are in good working condition, then you need to check the converter keys and the secondary windings of the transformers.
If in diagnosing a malfunction, it is necessary to disable the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required during work, and after they are finished, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- The TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the EAX60686904 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). Board repair and replacement of CPU chips: LGE3368A (Saturn-6); NAND Flash: HY27US08121B-TPCB; SPI Flash: W25X32VSSIG; SOUND: NTP3100 are manufactured with the necessary equipment, and the corresponding element base. Faults associated with the application of BGA processor soldering technologies can be localized by the heating method.
If the TV works normally from external devices, but does not tune into television channels, the TDFW-G235D 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.
Owners and users of the LG 32LD321 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!


SCHEMATIC MANUAL --> LG 32LD320, 32LD320-ZA, 32LD320N, 32LD320N-ZA, 32LD321, 32LD321-ZB Chassis LD91A


 The appearance of the MainBoard EAX60686904 is shown in the figure below:
EAX60686904
EAX60686904 can be used in TVs:
LG 32LD320 (Panel T315XW03 V1), LG 32LD320-ZA (Panel T315XW03), LG 32LH4000-ZA (Panel LC320WUN), LG 32LH2000 (Panel LK315T3LA57), LG 32LH2010 (Panel LK315T3LA57), LG 32LF2510 ZB (Panel LC320WUN (SA)(B3)), LG 37LH2000 (Panel LC370WXE (SB)(A1)), LG 19LD320 ZA (Panel M185B1-L02 Rev.C3), LG 26LH2000 (Panel T260XW02 V.R), LG 32LG2100 (Panel LC320WXN), LG 22LH2000 ZA (Panel V216B1-L02), LG 42LH2000 ZA.ARUVLH (Panel LC420WXE (SB)(A1)), LG 32LD321 32LD321-ZB (Panel T315XW03 V1), LG 26LD320 (Panel T260XW04 V.3), LG 19LH2000 19LH2000-ZA (Panel M185B1-L03).
The appearance of the power supply
Main features of the device LG 32LD321:
Installed matrix (LCD panel) T315XW03 V1.
The VIT71884.00 inverter is used to power the backlight, controlled by the OZ964SN PWM controller.
The necessary supply voltages for all nodes of the LG 32LD321 TV are generated by the EAX62106801 power module or its analogs using L6599D, HS01G (PFC), ICE3B0365J (Standby) microcircuits and power switches of the K5A60D, K13A60D type.
MainBoard - the main board (motherboard) is an EAX60686904 module, using CPU chips: LGE3368A (Saturn-6); NAND Flash: HY27US08121B-TPCB; SPI Flash: W25X32VSSIG; SOUND: NTP3100 and others.
The TDFW-G235D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: T315XW03 V1
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: VA, Normally Black, Transmissive
Active Area: 697.685x392.256 mm
Surface: Antiglare (Haze 11%), Hard coating (3H)
Brightness: 400 cd / m²
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 6.5 (G to G)
Frequency: 60Hz
Lamp Type: 4 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V