Thursday 20 February 2020

REPAIR / SERVICING TV LG 32LS359T

Technical description and composition of the LG 32LS359T TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 32LS359T
Chassis / Version: LD21C \ LC21B
Panel: LC320EXN (SE) (A2)
LED backlight: 6922L-0010A, 6920L-0148A
T-CON: 6870C-0414A
LED driver (backlight): 6917L-0097A
PWM LED driver: BD9395EFV
MOSFET LED driver: FDD850N10L
Power Supply (PSU): EAX64324701 LGP32L-12P
PWM Power: FAN7930, L6599AD, FSL106HR
MOSFET Power: STD10NM60D, STD7NM60N
Mainboard: EAX64664903
IC MainBoard: LGE2111A-T8, K4B1G1646G-BCKO, STA3808 WE, 25080 BVSIG, AP7173
Tuner: TDSN-G301D
Specifications 32LS359T
LG 32LS359T
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The LG 32LS359T 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.
With such manifestations, a malfunction is likely to be detected in the EAX64324701 power module. It is necessary to verify the presence of its output voltages and, if they are completely absent, check the power switches (STD10NM60D, STD7NM60N) and rectifier diodes for possible short circuit.
In case of breakdowns of semiconductors in the secondary circuits, the converter can usually work abnormally in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse often breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM) FAN7930, L6599AD, FSL106HR, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it on and immediately disappears
A malfunction is usually most likely in these cases at the backlight nodes of the display matrix. 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 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.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the EAX64664903 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). If it is not possible to replace the MB (SSB) board, you need to check the health of its elements - LGE2111A-T8, K4B1G1646G-BCKO, STA3808 WE, 25080 BVSIG, AP7173. Defective components should be replaced.
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 TDSN-G301D tuner. 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.
Owners and users of the LG 32LS359T TV should 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!



SCHEMATIC----------------------->LG 32LS359T Chassis LD21C.

LG 32LS3500/350S/350T/3510, 32LS3590/359S/359T, 32LS3500/350S/350T-ZA 32LS3510-ZB, 32LS3590/359S/359T-ZC.

SCHEMATIC-----------------------> LGP32L-12P EAY62512301 EAX64324701. Power supply


 The appearance of the MainBoard EAX64664903 is shown in the figure below:
EAX64664903
EAX64664903 can be used in TVs:
LG 32CS460T (Panel LC320WXN (SC)(A4)), LG 42LS3400 (Panel LC420DUN (SE)(R2)), LG 32LS3400 ZC (Panel LC320DXN (SE)(R2)), LG 32LS3500 (Panel LC320EXN (SE)(A2)), LG 32CS466 (Panel LC320WXN (SC)(A4)), LG 32LS3590 32LS3590-ZC.BRUDLJU (Panel T320XVN01.1), LG 32LS359T (Panel LC320EXN (SE)(A2)), LG 42CS460T 42CS460T-ZA (Panel LC420WUE (SC)(A3)).
The appearance of the power supply
Main features of the device LG 32LS359T:
Installed matrix (LED-panel) LC320EXN (SE) (A2).
The matrix control uses the Timing Controller (T-CON) 6870C-0414A.
The LED driver 6917L-0097A is used to power the backlight LEDs, it is controlled by the BD9395EFV PWM controller. As the power elements of the LED driver, keys of the FDD850N10L type are used.
The necessary supply voltages for all nodes of the LG 32LS359T TV are generated by the EAX64324701 power supply module or its analogs using FAN7930, L6599AD, FSL106HR microchips and power switches of the STD10NM60D, STD7NM60N type.
MainBoard - the main board (motherboard) is an EAX64664903 module, using LGE2111A-T8, K4B1G1646G-BCKO microcircuits, STA3808 WE, 25080 BVSIG, AP7173 and others.
The TDSN-G301D tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC320EXN-SEA2
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 697.685x392.256 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Brightness: 350 cd / m²
Contrast Ratio: 1200: 1
Display Colors: 16.7M (6-bit + Hi-FRC), CIE1931 68%
Response Time: 6 (G to G)
Frequency: 60Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V