Technical description and composition of the LG 22LG3000 TV, panel type and applicable modules. The composition of the modules.LG
Model: 22LG3000
Chassis / Version: LD84A
Panel: 1366x768 720 hd
Lamp backlight: 4 Lamp CCFL
Inverter (backlight): integrated into PSU;
PWM Inverter: OZ9938GN
MOSFET Inverter: AM4502C
Power Supply (PSU): 715T2783
PWM Power: LD7575A
MOSFET Power: STP10NK70ZFP
MainBoard: 715T3009-2
IC MainBoard: SPI Flash: MX25L3205D, EEPROM: 24C16
Tuner: FQD1116ME
Specifications 52LG5030
LG 22LG3000
General recommendations for repairing TV LCD
Possible malfunctions
- LG 22LG3000 does not turn on and does not show any signs of performance at all. Does not blink indicators and does not respond to control buttons.
In some of these cases, the main switching power supply, the 715T2783 module, is faulty. It is necessary to measure its output supply voltages, and in case of their absence, check the serviceability of power switches (STP10NK70ZFP) of converters and rectifier diodes for the probability of breakdown in PN semiconductor junctions.
In case of diode breakdowns in the secondary circuits, the converter can operate in emergency short-circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key usually 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 LD7575A are usually checked by replacing with new, or obviously working.
- There is no image, there is sound, it responds to the remote control, the channels are switched. In some cases, the image appears when you turn on and immediately disappears.
The defect can be caused by problems in the nodes or elements of the backlight of the display, or in the power supply of the lamps or the inverter.After checking all the electrolytic capacitors of the filters that are involved in the power supply to the inverter, you must ring in its converter power keys for breakdown and secondary windings of transformers for an open.
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 715T3009-2 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). In cases of attempts to repair the MB board (SSB), it is necessary to check the health of its elements - SPI Flash: MX25L3205D, EEPROM: 24C16 which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its conclusions with the board (it is diagnosed by heating).
Before replacing the FQD1116ME tuner, if there is no tuning to 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 independently repair the LG 22LG3000 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 22LG3000, 22LG3010 Chassis LD84A.
FIRMWARE SPI FLASH, EEPROM ---------------------------------> LG 22LG3000 LD84A, Main: 715T3009-2.
PSU SCHEMATIC --------------------------------------------------------> 715T2783 Power supply
The appearance of the MainBoard 715T3009-2 is shown in the figure below:715T3009-2
The appearance of the power supply
Main features of the device LG 22LG3000:
Installed matrix (LCD panel) 1366x768 720 hd.
To power the backlight, a converter is used, combined with a power supply, controlled by the OZ9938GN PWM controller. As power elements of the inverter, keys of the type AM4502C are used.
The necessary supply voltages for all nodes of the LG 22LG3000 TV are generated by the 715T2783 power supply module or its analogs using LD7575A microcircuits and power switches of the STP10NK70ZFP type.
MainBoard - the main board (motherboard) is a 715T3009-2 module using SPI Flash chips: MX25L3205D, EEPROM: 24C16 and others.
The FQD1116ME tuner provides TV reception and channel tuning.