Technical description and composition of the LG 37LH3000 TV, panel type and applicable modules. The composition of the modules.LG
Model: 37LH3000
Chassis / Version: LD91A / G
Panel: T370HW02 V.G
T-CON: T370HW02 VG CTRL BD
Power Supply (PSU): EAX55357705 / 3
MainBoard: EAX60686902 (0)
IC MainBoard: CPU: LGE3368A-LF-SF; RAM: HY5PS1G1631C; SPI FLASH: 25L32050M21
Tuner: TDFW-G235D
Specifications 37LH3000
LG 37LH3000
General recommendations for repairing TV LCD
LG TV made on the LD91A / G chassis, like many other electronic devices, it is advisable to start repairing by inspecting all external and internal elements. Sometimes, based on visible changes in the components of the device, it is possible to draw some conclusions and determine the direction of further troubleshooting even before the necessary measurements are taken. Experienced repairmen are often aware of the causes of the defect and possible consequences, for example, from ring cracks in the soldering of the leads of the elements, as well as from swollen capacitors or resistors burnt to coal dust and other external indirect signs.
In the absence of any signs of operability, when the LG 37LH3000 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 TV EAX55357705 / 3 power supply module. With the same manifestations, the power regulator of the control processor on the motherboard may be faulty. When diagnosing and repairing the power supply, after replacing the swollen capacitors of the filters of the secondary rectifiers (if any), you must first check the mains fuse. When it is broken, the power elements of transistors and rectifier bridge diodes should be checked for avalanche (thermal) breakdown.
In most cases, key breakdowns in switching power supplies (SMPS) do not occur for no reason and you should look for other faulty circuit elements that could provoke a defect. This can be dried electrolytic capacitors in the primary circuit, and faulty damper elements, as well as dangling resistors or punched semiconductor elements in the stabilization circuits. Possible defective PWM chip from the manufacturer.
Sometimes the LG 37LH3000 TV does not have an image, but there is sound, or the image appears and immediately disappears. In this case, there is a high probability of a malfunction of the backlight converter, or of the lamps themselves, which can be checked by replacement. In such cases, it is necessary to verify the serviceability of all electrolytic capacitors of the filter according to the power supply of the inverter itself, including in the power supply unit (power supply unit). It should be remembered that when the protection is turned off in order to diagnose a malfunction, there is always a risk of failure of the power elements of the inverter. After repair, it is necessary to restore all standard converter protection circuits.
Diagnosis and repair of the motherboard EAX60686902 (0) is carried out by checking the performance of the stabilizers or power converters of the module chips. In some cases, a software update is required. When repairing an MB board, you need to check its components SPI FLASH: 25L32050M21. Defective items should be replaced. If BGA chips are installed, their malfunction is usually localized by heating. If chips with BGA soldering technology are used, a problem in its implementation is detected by the local heating of the chip.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repair only to professionals with sufficient experience in the field of electronic equipment repair.
schematic diagram -------------> LG 37LH3000 Chassis LD91A.
CHASSIS : LD91A; MODEL : 37LH3000, 37LH3010, 37LH3020, 37LH3040, 37LH3000-ZA, 37LH3010-ZB, 37LH3020-ZD, 37LH3040-ZG
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)).
Main features of the device LG 37LH3000:
Installed matrix (LCD panel) T370HW02 V.G.
The matrix control uses the Timing Controller (T-CON) T370HW02.
The formation of the necessary supply voltages for all nodes of the LG 37LH3000 TV is carried out by the EAX55357705 power module, or its analogues.
MainBoard - the main board (motherboard) is an EAX60686902 module using CPU chips: LGE3368A-LF-SF; RAM: HY5PS1G1631C; SPI FLASH: 25L32050M21 and others.
The TDFW-G235D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: T370HW02 VG
Type: a-Si TFT-LCD, Panel
Diagonal size: 37 inch
Resolution: 1920x1080, FHD
Display Mode: AMVA, Normally Black, Transmissive
Active Area: 819.36x460.89 mm
Surface: Antiglare, 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: 14 pcs CCFL Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V