Technical description and composition of the LG 32LN542V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 32LN542V
Chassis / Version: LD31B
Panel: LC320DUE SF R1
LED backlight: 6916l-1437A (B2), 6916l-1438A (B1)
T-CON: LC500DUE SFR1 Control Merge
LED driver (backlight): integrated into PSU; 70.3V 400mA
PWM LED driver: MAP3202
MOSFET LED driver: FDT86106, AP18N20GH
Power Supply (PSU): EAX64905001 (2.8) - LGP32-13PL1 EAY62810301
PWM Power: SSC1S311A (PWM flyback), NR891D (PWM Step-down 24/12)
MOSFET Power: MDF11N65B
MainBoard: EAX64891306 (1.1) LGP32-13PL1
IC MainBoard: CPU: LGE2121-MC, DRAM: H5TQ2G63DFR, Flash: MX25L8006E, AUDIO: STA380BWF
Tuner: EBL61240503 TDSQ-G601D
Specifications 32LN542V
LG 32LN542V
General repair guidelines for TV LCD LED
If the LG 32LN542V does not turn on, no control lights on the front panel light up or blink, therefore, there is a very high probability of a malfunction of the EAX64905001 power supply module (2.8). In some cases, only the processor power regulator may be faulty. In the absence of swollen filter capacitors of the secondary rectifiers, the diagnostics of the power supply should be started by checking the fuse and, if it is broken, it is first necessary to check all the power semiconductor elements of the primary circuit - diodes and transistors for the possibility of an avalanche or thermal breakdown.
A breakdown of the power switch of the pulse converter is often triggered by other elements, for example, in the stabilization or control circuits of this switch, as well as by the damper elements in its drain and TPI winding.
In cases where the LG 32LN542V TV has lost its image, and the sound is there and all other functions are operational, there is a possibility of a malfunction of the LED driver (converter for powering the backlight LEDs of the LC320DUE SF R1 panel). When you turn on the TV, the image may appear briefly and disappear. It must be borne in mind that with such manifestations the LEDs themselves also fail.
A malfunction in the backlight circuits often occurs due to an open in the power circuit of the LED lines. It requires disassembling the panel and checking the LEDs themselves, the rations of their terminals, as well as the reliability of the connections in the connectors and rations of the terminals.
When trying to detect a break in the LED lines, it should be taken into account that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
The motherboard EAX64891306 (1.1) LGP32-13PL1 should be checked if there is no reaction to the remote control and function buttons, the standby indicator blinks or lights up constantly. In such cases, if the converters or power regulators of the microcircuit are working, a software update may be necessary.
In some cases, it is necessary to check or replace (if necessary) the elements of the MB board (SSB) - CPU: LGE2121-MC, DRAM: H5TQ2G63DFR, Flash: MX25L8006E, AUDIO: STA380BWF. 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 voltage at the terminals of the tuner EBL61240503 TDSQ-G601D. 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.
Attention to users! Self-repair of the LG 32LN542V TV without the appropriate qualifications and experience can lead to its complete non-repairability!
One of the typical malfunctions of the LG 32LN542V often occurs in LG's LED panel LC320DUE SF R1.
External manifestations: there is no image, the backlight does not work. In most such cases, the LEDs turn out to be malfunctioning, which during testing turn out to be either in a cliff or with broken internal zener diodes.
LEDs must be replaced, and the maximum current from the driver should be limited to 10-20%.
To reduce the backlight current in TVs with the LGP32-13PL1 power supply unit (EAX64905001), you can increase the resistance of the current sensor, which consists of a set of pairs of low-impedance resistors R822-R829, only 4 pairs of 3.9 + 4.3 Ohm.
Having repaired one pair, we increase the nominal value of the sensor by 25%, which proportionally reduces the current in the LEDs from 400 mA to 300 mA.
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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 32LN542V:
Installed matrix (LED panel) LC320DUE SF R1.
The matrix control uses the Timing Controller (T-CON) LC500DUE.
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 32LN542V 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: LGE2121-MC, DRAM: H5TQ2G63DFR, Flash: MX25L8006E, AUDIO: STA380BWF and others.
The tuner EBL61240503 TDSQ-G601D provides television reception and channel tuning.
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