Monday, 24 February 2020

REPAIR / SERVICING TV LG 42LB5800

Technical description and composition of the LG 42LB5800 TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 42LB5800
Chassis / Version: LT46B
Panel: LC420DUE (P6) (A4)
LED driver (backlight): integrated into PSU
PWM LED driver: iW7011, R5F100BCAFP
MOSFET LED driver: TK15A20D, FDT86106LZ
Power Supply (PSU): EAX64905801 3PAGC10126A LGP55-13LPB
PWM Power: ICE3BR4765JZ (Standby), R2A20133D (PFC), SSC9527S
MOSFET Power: STD13NM60N (PFC), STD10NM60N
MainBoard: EAX65610904 (1.0) EBT62987204
IC MainBoard: H5TQ4G63AFR, EEPROM: 24C256, SOUND: Audio: NTP7513
Tuner: TDJM-G101D EBL61400501
Specifications 42LB5800
LG 42LB5800
General repair guidelines for TV LCD LED
Possible manifestations of defects
- LG 42LB5800 does not turn on at all and does not show any signs of operability. Does not blink indicators and does not respond to control buttons.
In most of these cases, the EAX64905801 main switching power supply fails. It is necessary to measure its secondary output voltages, and if they are absent, check the operability of power switches (STD13NM60N (PFC), STD10NM60N) of converters and rectifier diodes for possible avalanche breakdown (KZ).
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during short circuit in the elements of the primary circuit, the mains fuse usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, power supply, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. PWM ICE3BR4765JZ (Standby), R2A20133D (PFC), SSC9527S can also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
As a rule, in such cases there is no display backlight. The reason can be both in the power supply 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 LED strips, to open all the transitions of the LEDs, several tens of volts or more are needed, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED transitions in forward bias, you can sometimes detect the presence of a PN junction of the protective zener diode by connecting the probes in the opposite direction. If the zener diode is broken or broken in short-circuit, then the LED is faulty and needs to be replaced.
- The TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the EAX65610904 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 they require checking or replacing (if necessary) the elements of the MainBoard board - H5TQ4G63AFR, EEPROM: 24C256, SOUND: Audio: NTP7513. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
If the TV works normally from external devices, but does not tune into television channels, the TDJM-G101D EBL61400501 tuner may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Attention to users! Self-repair of the LG 42LB5800 TV without the appropriate qualifications and necessary experience can lead to its complete non-repairability!


Schematic diagram ------------>  LG 42LB5800 Chassis .

LG 42LF5800 Panel HC420DUN VAN53-51XX; Main: EAX65610906(1.1) EBR78542102



 The appearance of the MainBoard EAX65610904 is shown in the figure below:
EAX65610904
EAX65610904 can be used in TVs:
LG 32LB582V ZG (Panel LC320DUE (FG)(A4)), LG 42LB570V (Panel LC420DUE (FG)(A4)), LG 42LB5800 (Panel LC420DUE (P6)(A4)), LG 42LB580V (Panel LC420DUE (FG)(A4)), LG 32LB570U 32LB570U-ZJ (Panel NC320DXN VSBP2), LG 39LB580V (Panel T390HVF02.0 HC390DUN-VCHS1), LG 32LB580V ZB (Panel LC320DUE (FG)(A4)).
The appearance of the power supply
Main features of the device LG 42LB5800:
Installed matrix (LED-panel) LC420DUE (P6) (A4).
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by the iW7011, R5F100BCAFP PWM controller. As the power elements of the LED driver, keys of the type TK15A20D, FDT86106LZ are used.
The necessary supply voltages for all nodes of the LG 42LB5800 TV are generated by the EAX64905801 power supply module or its analogs using ICE3BR4765JZ (Standby), R2A20133D (PFC), SSC9527S microcircuits and power switches of the STD13NM60N (PFC), STD10NM60N type.
MainBoard - the main board (motherboard) is an EAX65610904 module, using H5TQ4G63AFR microcircuits, EEPROM: 24C256, SOUND: Audio: NTP7513 and others.
Tuner TDJM-G101D EBL61400501 provides the reception of television programs and tuning to channels.