Technical description and composition of the LG 32LW340C TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 32LW340C
Panel: LC320DUE- (FJ) (M1)
LED driver (backlight): integrated into PSU
PWM LED driver: LC5910
Power Supply (PSU): EAX66752501 LGP32D-16CH1
PWM Power: 3S211
MOSFET Power: K8A65W
MainBoard: EAX66921904
IC MainBoard: CPU: LGE2135
Tuner: TDJS-H301F
Specifications 32LW340C
LG 32LW340C
General repair guidelines for TV LCD LED
Possible manifestations of defects
- LG 32LW340C does not turn on, the indicators on the front panel do not light or flash. The TV does not respond to the control buttons and the remote control.
With such manifestations, a malfunction is most likely to be detected in the EAX66752501 power module. It is necessary to measure its secondary output voltages, and if they are absent, check the power switches (K8A65W) and rectifier diodes in the converters for a short circuit.
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.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM) 3S211, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
Often in such cases, there is no LED backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the line of series-connected LEDs without a special current source, and for this purpose it is not safe to use any voltage sources above 12V for them. Then it remains only to open the panel and check each LED separately. Usually, Chinese 9V-powered multimeters light up a single 3-volt LED, if you connect the probes in the forward direction, the red probe to the anode, and the black to the cathode. In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of health. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- The indicator blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the EAX66921904 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). Often, the MB (SSB) card must be replaced in case of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - CPU: LGE2135 and replace failed chips with new ones. Some malfunctions may be due to the use of BGA soldering technologies in modern Main Board technologies. Typically, such defects are detected by local heating of the chip.
If a TDJS-H301F tuner is suspected of malfunction, first of all, it is necessary to verify the correctness of the software, as well as the presence of the necessary supply voltage levels and data exchange pulses with the processor via the I2C bus at the corresponding tuner pins.
Owners and users of the LG 32LW340C 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!
The appearance of the MainBoard EAX66921904 is shown in the figure below:EAX66921904
Main features of the device LG 32LW340C:
Installed matrix (LED-panel) LC320DUE- (FJ) (M1).
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the LC5910 PWM controller.
The necessary supply voltages for all nodes of the LG 32LW340C TV are generated by the EAX66752501 power module, or its analogs using 3S211 microcircuits and K8A65W type power switches.
MainBoard - the main board (motherboard) is an EAX66921904 module, using CPU chips: LGE2135 and others.
The TDJS-H301F tuner provides TV reception and channel tuning.
