Wednesday 19 February 2020

REPAIR / SERVICING TV LG 32LN540V

Technical description and composition of the LG 32LN540V TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 32LN540V
Chassis / Version: LD31B
Panel: LC320DUE (SF) (R1)
LED backlight: 6916l-1437A (B2), 6916l-1438A (B1)
T-CON: 6870C-0452A, LC500DUE-SFR1
LED driver (backlight): integrated into PSU; 70.3V 400mA
PWM LED driver: MAP3202
MOSFET LED driver: FDT86106, AP18N20GH
Power Supply (PSU): EAX64905001 - LGP32-13PL1 EAY62810301
PWM Power: SSC1S311A (PWM flyback), NR891D (PWM Step-down 24/12)
MOSFET Power: MDF11N65B
MainBoard: EAX64891306 (1.1)
IC MainBoard: Cpu: ENGINE LGE2121-MS Spi Flash: MXIC MX 25L8006B, Eeprom: 4256BRP (24C256)
Tuner: TDSQ-G601D (B)
Control: Remote: AKB73715603
Specifications 32LN540V
LG 32LN540V
General repair guidelines for TV LCD LED
Diagnostics of malfunctions and repairs LG 32LN540V, as well as other electronic devices, it is recommended to start with an external examination of the external and internal elements. Using visible changes in the state of components, it is usually possible to determine the further direction of troubleshooting and localization of the defect before the necessary measurements are taken. Electrolytic capacitors of filters with a swollen casing, as well as ring cracks formed in the soldered leads of heating elements, or a layer of coal on burnt resistors sometimes tell the repairman the causes of the malfunction and possible consequences.
If the 32LN540V TV does not turn on, does not make any sounds when it is turned on, and also no indicators on the front panel light or blink - there is a high probability of a malfunction in the power module. In some cases, only the stabilizer or power converter of the control processor may be malfunctioning, which is typical for some LG models. First of all, it is necessary to replace the swollen capacitors of the rectifier filters, if any. If the mains fuse is cut off in the power supply, in most cases a breakdown of the power key (s) is detected, which can be integrated with the PWM controller, or a separate field-effect transistor can be used. The rectifier bridge diodes and the electrolytic capacitor of the mains rectifier filter should also be checked.
The reasons for the breakdown of the power switch in pulsed power supplies (IIPS) can be different, for example, a malfunction of semiconductor cells or electrolytic capacitors in the stabilization circuits of the primary circuit, as well as a failure in the operation of the PWM controller chip or broken resistors in its bundle.
If there is no image when you turn on the LG 32LN540V, or it appears for a second and disappears, but there is sound, most likely there is a malfunction in the backlight LED circuit of the LC320DUE SF R1 panel, or in their power converter. It is necessary to check the electrolytic capacitors of the filter of the secondary rectifiers in the general power supply unit.
In most cases of lack of backlight, it becomes necessary to disassemble the panel in order to check the LEDs, connectors, loops and all contact connections. If one or several LEDs does not work in one line, therefore, they are broken and should be replaced.
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.
Attention to the owners! Attempts to repair the LG 32LN540V TV independently are not recommended by the manufacturer and can lead to serious negative consequences!
One of the typical malfunctions of the LG 32LN540V often occurs in the LG LC320DUE SF R1 LED panel.

External manifestations: there is no image, the backlight does not work. In most of these cases, the LEDs turn out to be faulty, which, when tested, turn out to be either open or with broken internal zener diodes.
LEDs must be replaced, and the maximum current from the driver is limited to 10-20%.


More details on this page


SCHEMATIC MANUAL -------> LG 32LN54**, 32LN54**-Z*, 32LN536*, 32LN536*-Z* Chassis LD31B/LD36B.


PSU SCHEMATIC --------------> LG LGP32-13PL1, LGP32I-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 32LN540V:
Installed matrix (LED-panel) LC320DUE (SF) (R1).
The matrix control uses the Timing Controller (T-CON) 6870C-0452A.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the MAP3202 PWM controller. As power elements of the LED driver, keys of the type FDT86106, AP18N20GH are used.
The necessary supply voltages for all nodes of the LG 32LN540V TV are generated by the EAX64905001 power module or its analogs using SSC1S311A (PWM flyback), NR891D (PWM Step-down 24/12) microcircuits and MDF11N65B type power switches.
MainBoard - the main board (motherboard) is an EAX64891306 module, using Cpu chips: ENGINE LGE2121-MS Spi Flash: MXIC MX 25L8006B, Eeprom: 4256BRP (24C256) and others.
The TDSQ-G601D (B) tuner allows you to receive television programs and tune to channels.
Information from an alternative source:
LG 32LN540V Chassis LD31B; LG 32LA615V
Panel Type (Matrix): LC320DUE (SF) (R1)
Motherboard: EAX64891306; EAX648991304 (1.1), LGE2121-MS, MX25L8006E, H5TQ2G63DFR, Tuner: TDSQ-G601D (B)
T-con: LC500DUE-SFR1,
PSU: EAX64905001
Remote control: AKB73715603 part1, part2,
Additional technical information about the panel:
Brand: LG Display
Model: LC320DUE-SFR1
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1920x1080, FHD
Display Mode: IPS, Normally Black, Transmissive
Active Area: 698.4x392.85 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Brightness: 300 cd / m²
Contrast Ratio: 1200: 1
Display Colors: 16.7M (8-bit), CIE1931 68%
Response Time: 6 (G to G)
Frequency: 60Hz
Lamp Type: WLED Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V