Tuesday 18 February 2020

REPAIR / SERVICING TV LG 32LH2000

Technical description and composition of the LG 32LH2000 TV, panel type and applicable modules. The composition of the modules.
LG
Model: 32LH2000
Chassis / Version: LD91A
Panel: LK315T3LA57 // LC320WXN (SB) (A3)
Lamp backlight: EEFL
T-CON: LC320WXN-SBAI CONTROL 6870C-0238B
Inverter (backlight): RDENC2590 TPZZ // LC320WXN 6632L-0528A
Power Supply (PSU): LGP32-09P EAX55176301 / 01
PWM Power: ICE3B0365J (Standby), L6599D (PWM Resonant), L6562A (PFC)
MOSFET Power: TK13A60D (PFC), TK6A60D
MainBoard: EAX60686904 (2) // EAX60686902 (0)
IC MainBoard: CPU: LGE3368A, Nand: HY27US08121B, DDR: HY5PS1G1631CFP
Tuner: TDFW-G235D
Control: AKB69680403
Specifications 32LH2000
LG 32LH2000
General recommendations for repairing TV LCD
LG with the LD91A chassis, like other TVs, it is advisable to start repairing with a careful examination of the external and internal elements and modules. According to some external signs of a change in the state of some elements, it is sometimes possible to make assumptions about the nature of the defect, as well as determine the further direction of the troubleshooting. If charred resistors, swollen electrolytic or cermet capacitors, ring cracks in the soldered terminals of transformers or heating elements are detected, it is advisable to establish the causes and consequences of the malfunction that has arisen, as well as to check the connected elements and assemblies.
In the case when the 32LH2000 does not turn on, does not respond to the remote control and buttons on the front panel, does not blink bulbs and does not show any signs of operability, the EAX55176301 / 01 power supply module is probably faulty in this case. If it is serviceable with such manifestations, it is necessary to check the stabilizer (converter) of the processor power supply on the motherboard. It is advisable to start the troubleshooting of the power supply module by checking the condition of the electrolytic capacitors of the rectifier filters and the mains fuse. Defective capacitors should be replaced. If the mains fuse is broken, it is necessary to check first of all the power semiconductor elements - rectifier diodes and transistors, which are often found in such a state of breakdown.
The reasons for the breakdown of the power switch in pulsed power supplies (IIPS) can be different, for example, a malfunction of semiconductor cells or electrolytic capacitors in the stabilization circuits of the primary circuit, as well as a failure in the operation of the PWM controller chip or broken resistors in its bundle.
If when you turn on the LG 32LH2000 there is no image, or it appears for a second and disappears completely, but there is sound, most likely either the backlight or the power converter (inverter) are faulty. It is necessary to check the electrolytic capacitors of the filter of the secondary rectifiers in the general power supply unit. When diagnosing a malfunction of the inverter with the protection off, special precautions must be taken, because there is a risk of failure of the power elements of the inverter. After the diagnosis, it is imperative to restore the protection circuits for the inverter to operate normally.
When trying to repair the motherboard, you should first check the serviceability of linear stabilizers or power converters of microcircuits and, if necessary, update the software (software). In some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - CPU: LGE3368A, Nand: HY27US08121B, DDR: HY5PS1G1631CFP with new or obviously working ones. In cases where BGA technologies are used, defects are usually localized by the heating method.
Owners and users of the LG 32LH2000 TV must 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 ------------------->  LG CHASSIS: LD91A; 32LH2000 32LH2000-ZA, 32LH2010 32LH2010-ZB SERVICE MANUAL

SCHEMATIC ------------------->  LGP32-09P POWER SUPPLY



 The appearance of the MainBoard EAX60686902 is shown in the figure below:
EAX60686902
EAX60686902 can be used in TVs:
LG 37LH3000 (Panel T370HW02 V.G), LG 32LH2000 (Panel LK315T3LA57), LG 32LF2510 ZB (Panel LC320WUN (SA)(B3)), LG 42LF2510 (Panel LC420WUE (SB)(C1)), LG 47LH3000 (Panel LC470WUE), LG 32LH3010 (Panel LC320WUN (SA)(B2)), LG 37LH2010 37LH2010-ZB.BRUVLJU (Panel LC370WXE (SB)(A1)).
PSU Advanced
The LGP32-09P power supply module is made using a Power Factor Correction (PFC) scheme to eliminate multiple AC harmonics introduced into the power supply by the device. The PFC assembly is a Step-Up Converter based on the L6562A PWM controller, which evenly distributes high-frequency impulses of the charging current of the electrolytic capacitor of the mains voltage rectifier filter within a 50 Hz period. The current of its charge in this case will already be determined not by its reactance (usually 10-30 ohms for the network frequency), but by the elements of the converter. As a result, a change in the amplitude of the pulses (envelope) of the consumed current of the converter will repeat the shape and phase of the input sinusoidal voltage. The availability of an increased voltage (about + 380V) in the operating mode on the capacitor of the line filter indicates the serviceability of the PFC node.
The appearance of the power supply
Main features of the device LG 32LH2000:
Installed matrix (LCD panel) LK315T3LA57 or LC320WXN (SB) (A3).
The matrix control uses the Timing Controller (T-CON) LC320WXN-SBAI.
The RDENC2590 inverter is used to power the backlight.
The necessary supply voltages for all nodes of the LG 32LH2000 TV are generated by the LGP32-09P power supply module or its analogs using ICE3B0365J (Standby), L6599D (PWM Resonant), L6562A (PFC) microcircuits, and TK13A60D (PFC), TK6A60D type power switches.
MainBoard - the main board (motherboard) is an EAX60686904 module using CPU chips: LGE3368A, Nand: HY27US08121B, DDR: HY5PS1G1631CFP and others.
The TDFW-G235D tuner provides TV reception and channel tuning.
Information from an alternative source:
LG 32LH2000-ZA Chassis LD91A
Panel Type (Matrix): LC320WXN (SB) (A3)
Motherboard: EAX60686902 (0) EBR61248530, Tuner: TDFW-G235D
T-con: LC320WXN-SBAI CONTROL 6870C-0238B
Invertor: LC320WXN 6632L-0528A, IR: YW94197481A
PSU: LGP32-09P EAX55176301 / 10
Remote control: AKB69680403
Additional technical information about the panel:
Brand: SHARP
Model: LK315T3LA57
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: ASV, Normally Black, Transmissive
Active Area: 697.68x392.26 mm
Surface: Antiglare, Hard coating (2H)
Brightness: 500 cd / m²
Contrast Ratio: 2500: 1
Display Colors: 16.7M (8-bit)
Response Time: 7 (G to G)
Lamp Type: 10 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V