Sunday 23 February 2020

REPAIR / SERVICING TV LG 39LB580V

Technical description and composition of the LG 39LB580V TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 39LB580V
Chassis / Version: LD46B
Panel: T390HVF02.0 HC390DUN-VCHS1
LED backlight: LG Innotek DRT 3.0 39
T-CON: T420HVN06.1
LED driver (backlight): integrated into PSU
PWM LED driver: BD9486F
MOSFET LED driver: 4NF20, MDD3752
Power Supply (PSU): EAX65423701 (2.0) LGP3942-14PL1
PWM Power: MAP8800 (PFC), FA6A01N
MOSFET Power: TK7P60W
MainBoard: EAX65610904 (1.0) EBR78668701
IC MainBoard: H5TQ4G63AFR, 24C256, NTP7513
Tuner: EBL61400501 TDJM-G101D
Control: Wi-fi: TWFM-B006D
Specifications 39LB580V
LG 39LB580V
General repair guidelines for TV LCD LED
Possible manifestations of defects
- LG 39LB580V TV does not turn on. There are no signs of operability. The indicators on the front panel do not light or flash, the TV does not respond to the remote control and control buttons.
Failure in such cases should begin to be sought in the power supply circuits of the EAX65423701. Then we recommend that you measure its output voltages and, if they are absent, you should check the health of the power switches (TK7P60W) and rectifier diodes of the converters for possible short circuit.
In case of breakdowns in the secondary circuits, the converter, as a rule, can emergency work in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse usually breaks.
Breakdown of power switches (MosFet) in pulsed sources is sometimes caused by malfunctions of other circuit elements, for example, in circuits supplying a PWM controller, frequency-setting or damper ones, as well as in negative feedback (OOS) stabilization circuits. PWM controllers (PWM) MAP8800 (PFC), FA6A01N, if they do not have visible damage to the case and open short circuit between the terminals, are usually checked by replacement.
- 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.
In most of these cases, a malfunction is detected in the nodes and backlight elements of the LED panel. 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 lines for breaks without disassembling the panel, for example, a current source will help. It is impossible to open series-connected PN junctions with a simple multimeter, a voltage of the order of several tens of volts is required.
- The TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly 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). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the elements H5TQ4G63AFR, 24C256, NTP7513. BGA chip malfunctions are usually easy to detect by warming up.
If there is no reception of television channels, but the TV works properly from external devices, first of all you need to check the voltage of the tuner EBL61400501 TDJM-G101D and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Attention to users! Self-repair of the LG 39LB580V TV without the appropriate qualifications and necessary experience can lead to its complete non-repairability!


Backlight Current Limit:
In televisions with power supplies LGP3942-14PL1 (EAX65423701), the backlight current sensor - the resistor block R811-R818 consists of four pairs of 4.3 Ohm each. You can reduce the backlight current by 25% by removing one pair of resistors.



schematic diagram ------------->  LG 39LB5800, 39LB580V, 39LB582V -Z* CHASSIS LD46B


 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 39LB580V:
The matrix (LED panel) T390HVF02.0 HC390DUN-VCHS1 is installed.
The matrix control uses the Timing Controller (T-CON) T420HVN06.1.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the BD9486F PWM controller. As power elements of the LED driver, keys of the type 4NF20, MDD3752 are used.
The necessary supply voltages for all nodes of the LG 39LB580V TV are generated by the EAX65423701 power module or its analogs using MAP8800 (PFC), FA6A01N microcircuits and TK7P60W type power switches.
MainBoard - the main board (motherboard) is an EAX65610904 module, using H5TQ4G63AFR, 24C256, NTP7513 and others.
The tuner EBL61400501 TDJM-G101D provides reception of television programs and tuning to channels.