Sunday 23 February 2020

REPAIR / SERVICING TV LG 39LN540V

Technical description and composition of the LG 39LN540V TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 39LN540V
Chassis / Version: LD31B / LC36B / LL36B
Panel: HC390DUN-VCFP1-11XX
LED backlight: LG Innotek POLA2.0 39 A-Type / B-Type Rev 0.0 2012.11.14
T-CON: V390HJ1-CE1
LED driver (backlight): integrated into PSU; 157V 341mA
PWM LED driver: MAP3202 (MAP3202SIRH)
MOSFET LED driver: FDT86106
Power Supply (PSU): EAX64905301 (2.3) LGP3739-13PL1
PWM Power: SSC1S311A (PWM flyback), NR891D (PWM Step-down 24/12)
MOSFET Power: MDF11N65B / STP10NM60N
MainBoard: EAX64891306 (1.1)
IC MainBoard: LGE2121-MS, Flash: 25Q80BVSIG, EEPROM: 24C256BRP, NAND Flash: H27U1G8F2CTR, Sound: STA3808WF
Tuner: EBL61240503 TDSQ-G601D
Control: Remote: AKB73715603
Specifications 39LN540V
LG 39LN540V
General repair guidelines for TV LCD LED
LG 39LN540V, like other televisions, it is advisable to start repairing by inspecting external and internal elements and modules. Often, based on certain external signs, it may be possible to draw certain conclusions about the reasons for the failure of certain elements of the circuit even before the necessary measurements are made, which will determine the further algorithm for troubleshooting and localizing the defect. Ring cracks in the soldering of the leads of the heating elements, swollen electrolytic capacitors, a charred paint layer on the resistors - all this for the repairman can be a significant clue in the assumptions about the causes and consequences of the malfunction.
A malfunction of the power supply is often manifested corny - the TV does not turn on, does not make any sounds, does not light up and does not blink with any indicators. When repairing the power supply, it is advisable to start the diagnostics by checking the mains fuse and the electrolytic capacitors of the filters of the converter secondary rectifiers. In the event of a fuse breaking, the reason should be sought in the power semiconductor elements of the pulse converter of the main power supply. First of all, it is necessary to check the diodes of the rectifier bridge of the mains voltage and the power key (s) of the converter. The complete inoperability of the power supply unit can be caused by a short circuit in the power elements in the primary circuit, followed by an open fuse, or a short circuit in the loads.
It should be remembered that in the practice of repair, usually the power switches in switching power supplies (SMPS) do not fail due to their poor quality and, in such cases, it is necessary to look for the cause that led to a malfunction and provoked a breakdown of the key. Most often, the culprits of the accident are dried electrolytic capacitors or dangling resistors in the primary circuit, or the SC1S311, NR891D PWM controller chip itself may be faulty. It is also necessary to check all the semiconductor elements of the stabilization circuit in the primary and secondary circuit.
If there is no image when you turn on the LG 39LN540V, or it appears and immediately disappears, but there is sound, most likely there is a malfunction in the backlight LED circuit of the HC390DUN-VCFP1-11XX panel, or in the LED node of the driver - their power converter.
In case of breaks in the LED circuit, a complete disassembly of the panel is required, the LEDs are checked for an open circuit, as well as the reliability of the connections in the connectors and rations of the terminals.
To detect a break in the LED lines without disassembling the panel, a current source is required. It is impossible to open transitions connected in series with a simple multimeter; voltage of several tens of volts is necessary.
In cases of attempts to repair the motherboard EAX64891306 (1.1), it is necessary to check the operability of the linear stabilizers and power converters of its microcircuits and, if possible, update the software (software). BGA chips can sometimes be diagnosed with local heating.

In some cases, it is necessary to check or replace (if necessary) the elements of the MB (SSB) board - LGE2121-MS, Flash: 25Q80BVSIG, EEPROM: 24C256BRP, NAND Flash: H27U1G8F2CTR, Sound: STA3808WF. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
If you suspect a malfunction of the tuner EBL61240503 TDSQ-G601D, first of all, you need to make sure the software is correct, as well as the presence of the necessary voltage levels at the corresponding terminals of the tuner.
We recommend the owners of the 39LN540V TV for repair only to qualified specialists with experience! Self-repair attempts without the appropriate knowledge and skills can lead to serious negative consequences!


schematic diagram ------------------>  LG CHASSIS LD31B/LD36B MODEL 39LN54** 39LN54**-Z*.

schematic diagram PSU ---------->  LG 37/39/42 Inch LGP3739-13PL1, LGP42-13PL1


 The appearance of the MainBoard EAX64891306 is shown in the figure below:
EAX64891306
EAX64891306 can be used in TVs:
LG 32LN540V (Panel LC320DUE (SF)(R1)), LG 42LN542V-ZD (Panel LC420DUE SFR3), LG 32LN541V (Panel LC320DUE (SF)(R1)), LG 42LA615V (Panel LC420DUE (SF)(U2) ), LG 32LA615V (Panel LC320DUE (SF)(U2)), LG 42LN540V (Panel LC420DUE (SF)(R1)), LG 42LN541V (Panel LC420DUE (SF)(R1)), LG 47LN540V (Panel LC470DUE (SF)(R1)), LG 32LB530U ZA (Panel LC320DXE (SG)(R1)), LG 39LN540V (Panel HC390DUN-VCFP1-11XX), LG 32LA643V (Panel LC320EUN (SF)(F1)), LG 32LN542V (Panel LC320DUE SF R1), LG 47LA615V (Panel LC470DUE (SF)(U2)), LG 47LA643V ZB (Panel LC470EUN (SF)(F2)), LG 32LN541U ZB (Panel HC320DXN-VHFP1 - 21XX / HC320DXN-VHFPA - 21XX), LG 32LN536U (Panel NC320DXN (SA)(P1)), LG 37LN541U (Panel LC370DXE (SF)(R1)).
The appearance of the power supply
Main features of the device LG 39LN540V:
Installed matrix (LED panel) HC390DUN-VCFP1-11XX.
The matrix control uses the Timing Controller (T-CON) V390HJ1-CE1.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by the MAP3202 PWM controller (MAP3202SIRH). As the power elements of the LED driver, keys of the FDT86106 type are used.
The necessary supply voltages for all nodes of the LG 39LN540V TV are generated by the EAX64905301 power module or its analogs using SSC1S311A (PWM flyback), NR891D (PWM Step-down 24/12) microcircuits and power switches of the MDF11N65B / STP10NM60N type.
MainBoard - the main board (motherboard) is an EAX64891306 module, using LGE2121-MS chips, Flash: 25Q80BVSIG, EEPROM: 24C256BRP, NAND Flash: H27U1G8F2CTR, Sound: STA3808WF and others.
The tuner EBL61240503 TDSQ-G601D provides television reception and channel tuning.
Information from an alternative source:
LG 39LN540V Chassis LD31B
Panel Type (Matrix): HC390DUN-VCFP1-21XX
Motherboard: EAX64891306 (1.1) EBR76922709, Tuner: TDSQ-G601D (B) EBL61240503
T-con: V390HJ1-CE1
PSU: P / N: 3PCR00108A EAX54905301 (2.2)
Remote control: AKB73715603