Friday 28 February 2020

REPAIR / SERVICING TV LG 42LV369C

Technical description and composition of the LG 42LV369C TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 42LV369C
Panel: T420HW08 V.9
LED backlight: 74.42T13.004-0-CS1 - LG INNOTEK 42NCH 5630PKG 2CUP 60EA Rev0.1 110603
T-CON: 46T03-C0K, T460HW03 VF CTRL BD
LED driver (backlight): T315HW07 V8 Led 31T14-D06
PWM LED driver: MAX16814, RM5103
MOSFET LED driver: P3506DD, P1825AS
Power Supply (PSU): EAX63729001 -8 LGP4247-11SPL EAY62171601
PWM Power: FAN7930B (PFC), 3BR4765JZ (Standby), L6599AD
MOSFET Power: K10A60D
MainBoard: EAX64290501 (0) EBR74332101 SAA35645811 SAA35662401 SAA35651501
IC MainBoard: CPU: LGE107DC-RP, DDR: H5TQ1G63DFR-PBC, Nand: K9F1G08U0D, FLASH 25Q80, EEPROM 24C16
Tuner: TDTJ-S001D
Control: IR: 1BF-3001A
Specifications 42LV369C
LG 42LV369C
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 42LV369C TV does not turn on at all. The control lights do not light or flash. The TV on the remote control and the control panel buttons do not respond.
Often in such cases, the EAX63729001 power module is faulty. It is then necessary to measure its output voltages and, if they are absent, check the power switches (K10A60D) and the rectifier diodes of the converters for a short circuit probability.
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually work normally in emergency short circuit mode. There are no output voltages. And with a short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and less often the current sensor at the source of the key.
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 chips FAN7930B (PFC), 3BR4765JZ (Standby), L6599AD are usually checked by replacing with new, or obviously working.
- There is no image, there is sound, it responds to the remote. Or the image may appear for a second when turned on and immediately disappears.
Usually in such cases, a malfunction is detected in the backlight nodes of the LED panel. The reason can be both in the power of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
To check the health in the LED circuit, it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED individually with a simple Chinese multimeter (powered by 9 volts) in the P-N-junction test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. A zener diode PN junction indirectly indicates a LED-a
- The indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the EAX64290501 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). Sometimes it is necessary to check or replace (if necessary) the elements of the MainBoard board: CPU: LGE107DC-RP, DDR: H5TQ1G63DFR-PBC, Nand: K9F1G08U0D, FLASH 25Q80, EEPROM 24C16. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
In the absence of tuning to the channels of on-air or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltages on the terminals of the TDTJ-S001D tuner. It is also necessary to check the presence of pulses of data exchange between the tuner and the processor via the I2C bus using an oscilloscope.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Entrust repair to professionals with sufficient experience in the field of repair of electronic equipment.
To reduce the backlight current in LED drivers with a PWM controller MAX16814 (TSSOP20 MAX16814B), it is necessary to proportionally increase the total resistance of the resistors from terminal 10 (SETI) to the housing. The maximum current in each of the four channels (in milliamps) for the resistance Rseti (in kilo-ohms) is determined from the ratio 1500 / Rseti.


The appearance of the MainBoard EAX64290501 is shown in the figure below:
EAX64290501
EAX64290501 can be used in TVs:
LG 32LV2500-ZA (Panel T315XW06 V.3), LG 37LV3500-ZA (Panel T370HW05 V.1), LG 42LV3400-ZA (Panel T420HW08 V.1), LG 32LK530 (Panel LC320WUD (SC)(A3)), LG 37LK430 (Panel LC370WUE), LG 32LK451 ZA (Panel T315HW04 V.9), LG 42LV3551 (Panel LC420EUN (SD) (V3)), LG 47LW4500 (Panel LC470EUF (SD)(F2)), LG 32LK551 ZB (Panel LC320WUD (SC)(A2)), LG 42LV3500 (Panel LC420EUN (SD)(V3)), LG 42LK551 ZB (Panel V420H2-LH5), LG 42LK451 42LK451-ZG.BRUYLJU (Panel T420HW09 V0), LG 42LK530 (Panel LC420WUF (SC)(A2)), LG 47LK950 ZA (Panel LC470WUF (SD)(P1)), LG 32LW4500 ZB (Panel LC320EUD (SD)(P1)), LG 42LW4500 ZB (Panel LC420EUF (SD)(PX)), LG 42LV4500 DA (Panel LC420EUF (SD)(A1)), LG 32LV4500 (Panel LC320EUD (SD)(A4)), LG 42LV369C (Panel T420HW08 V.9).
The appearance of the power supply
Main features of the device LG 42LV369C:
Installed matrix (LED-panel) T420HW08 V.9.
The matrix control uses the Timing Controller (T-CON) 46T03-C0K.
The LED driver T315HW07 is used to power the backlight LEDs, it is controlled by the PWM controller MAX16814, RM5103. As power elements of the LED driver, keys of the type P3506DD, P1825AS are used.
The necessary supply voltages for all nodes of the LG 42LV369C TV are generated by the EAX63729001 power module or its analogs using FAN7930B (PFC), 3BR4765JZ (Standby), L6599AD microcircuits and K10A60D type power switches.
MainBoard - the main board (motherboard) is an EAX64290501 module, using CPU chips: LGE107DC-RP, DDR: H5TQ1G63DFR-PBC, Nand: K9F1G08U0D, FLASH 25Q80, EEPROM 24C16 and others.
The TDTJ-S001D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: T420HW08 V9
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: AMVA3, Normally Black, Transmissive
Active Area: 930.24x523.26 mm
Brightness: 300 cd / m²
Display Colors: 16.7M (8-bit)
Frequency: 60Hz
Lamp Type: WLED Embedded (LED Driver)