Technical description and composition of the LG 32LN5400 TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 32LN5400 ZA
Chassis / Version: LD36B
Panel: LC320DUE (SF) (R1)
LED backlight: 6916l-1437A (B2), 6916l-1438A (B1)
T-CON: 6870C-0452A
LED driver (backlight): integrated into PSU; 70.3V 400mA
PWM LED driver: MAP3202
MOSFET LED driver: FDT86106, AP18N20GH
Power Supply (PSU): EAX64905001 (2.7) LGP32-13PL1 EAY62810301
PWM Power: SSC1S311A (PWM flyback), NR891D (PWM Step-down 24/12)
MOSFET Power: MDF11N65B
MainBoard: EAX64891403 (1.0)
IC MainBoard: CPU: LGE2121-MS A7MjD43ZC, NAND Flash: H27U1G8F2CTR, SPI Flash: MX25L8006E, EEPROM: 4256BRP, LGE2121-MS, STA3808WF
Tuner: TDSS-G501D
Specifications 32LN5400
LG 32LN5400
General repair guidelines for TV LCD LED
An external examination of the external and internal elements should be carried out in a timely manner before the start of operations for their dismantling. In some cases, visible external damage to the elements can indicate the direction of troubleshooting and localization of the defect even before the start of the necessary measurements at the control points of electronic circuit nodes. Experienced repairmen are often aware of the causes of the defect and possible consequences, for example, from ring cracks in the soldered terminals of the elements, as well as from swollen capacitors or resistors burnt to coal dust and other external signs of certain malfunctions.
In cases where the LG 32LN5400 TV does not turn on, does not respond to the remote control and buttons, no indicators on the front panel are lit or blinking, and there are no sounds and no signs of operability when turning on, the EAX64905001 power supply module (2.7) is most likely to be faulty or there is no standby power. Diagnostics and repair of the common power supply should always begin with a check of the mains fuse and the condition of the electrolytic capacitors of the secondary rectifier filters. Defective and swollen capacitors should be replaced with new ones. If the fuse breaks, it is advisable to check for a breakdown, first of all, all the power semiconductor elements of the converter and the diode bridge of the rectifier network, as well as the large electrolytic capacitor of the filter of the rectifier network.
Power switches in switching power supplies (SMPS) fail extremely rarely for no reason and, if they are broken, it is necessary to look for a malfunction in the stabilization circuits by checking electrolytic capacitors, semiconductor devices, and resistors in the primary circuit. The reason may be a malfunction of the PWM controller SSC1S311, which can only be checked by replacing it with a new or obviously working one.
If the LG 32LN5400 does not have an image, there is sound and the channels switch, there is a possibility of a malfunction in the backlight LED circuit of the LC320DUE (SF) (R1) panel, or their power converter - LED driver. Sometimes, when turned on, the image appears and immediately disappears. In such cases, it is necessary to check the electrolytic capacitors of the power filter of the LED driver itself, including in the secondary rectifier of the main PSU.
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.
Repair of the EAX64891403 (1.0) motherboard should begin with the diagnosis and verification of all linear stabilizers and power converters of its microcircuits. Sometimes it may be necessary to update the software (software) - flashing FLASH or EEPROM.
Often, the MB (SSB) card needs to be replaced in case of complex faults that are difficult to detect. When trying to repair, you should check its elements - CPU: LGE2121-MS A7MjD43ZC, NAND Flash: H27U1G8F2CTR, SPI Flash: MX25L8006E, EEPROM: 4256BRP, LGE2121-MS, STA3808WF and replace failed chips with new ones. Some malfunctions may be due to the use of BGA soldering technologies in modern Main Board technologies. Typically, such defects are detected by local heating of the chip.
If the TV works normally from external devices, but does not tune into television channels, the TDSS-G501D tuner may malfunction. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals. Sometimes the cause of the inoperability of the tuner may be a software failure.
Owners and users of the LG 32LN5400 TV must remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!
One of the typical malfunctions of the LG 32LN5400 ZA often occurs in the LG 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, 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 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.
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 EAX64891403 is shown in the figure below:EAX64891403
EAX64891403 can be used in TVs:
LG 32LN540B (Panel LC320DXE (SF) (R1)), LG 32LN5400 ZA (Panel LC320DUE (SF) (R1)).
The appearance of the power supply
Main features of the device LG 32LN5400:
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 the power elements of the LED driver, keys of the type FDT86106, AP18N20GH are used.
The necessary supply voltages for all nodes of the LG 32LN5400 TV are generated by the EAX64905001 power supply 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 EAX64891403 module, using CPU chips: LGE2121-MS A7MjD43ZC, NAND Flash: H27U1G8F2CTR, SPI Flash: MX25L8006E, EEPROM: 4256BRP, LGE2121-MS, STA3808WF.
The TDSS-G501D tuner 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