Technical description and composition of the LG 42LS345T TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 42LS345T
Chassis / Version: LD21C
Panel: HC420DUN-SLCP1 11XX
LED backlight: LG lnnotek 42 NDE Rev 0.3 A Type 2012.07.13 / B Type 2012.07.30
T-CON: 6870C-0401C - 32/37/42/47/55 / FHD TM120 Ver0.3
LED driver (backlight): integrated into PSU
PWM LED driver: MAP3202
MOSFET LED driver: MDD5N40
Power Supply (PSU): EAX64770201 (1.8) - LGP42P-12LPB - EAY62713701
PWM Power: SC1S311
MOSFET Power: MDF10N65F
MainBoard: EAX64910001 (1.0) - EBR75084309 4162
IC MainBoard: CPU: LGE2111A-T8, Nand: H27U1G8F2BTR, DDR: K4B1G1646G-BCK0, SPI: 25Q80
Tuner: TDSS-G101D
Control: AKB73655861
Specifications 42LS345T
LG 42LS345T
General repair guidelines for TV LCD LED
If the LG 42LS345T 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 power supply module EAX64770201 (1.8) - LGP42P-12LPB - EAY62713701. In some cases, only the processor power regulator may be faulty. After checking the mains fuse and power elements of the primary power supply circuit, it should also check the absence of a short circuit in the loads of the secondary rectifiers.
It should be borne in mind that in the practice of repair it is extremely rare that key transistors in switching power supplies (SMPS) fail for no reason that should be sought by checking other components, for example, a breakdown of the key can provoke faulty elements of the damper circuits, or dried electrolytic capacitors or dangling primary resistors BP circuits involved in the stabilization process. In this case, all semiconductor elements of the strapping of the SC1S311 PWM controller microcircuit are subject to verification, which it is desirable to verify by replacement.
If the image appears and immediately disappears when the TV is turned on, or it is initially absent when it is turned on, but the sound has other functions, there is a high probability of a malfunction of the display backlight LEDs or the LED driver (HC420DUN-SLCP1 11XX panel backlight power converter).
Often in the absence of backlighting, disassembling the panel is required. It is necessary to check the serviceability of the transitions of the LEDs, as well as the reliability of the contact connections in the rulers and connectors.
To check the health in the LED circuit, it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED individually with a simple Chinese multimeter (powered by 9 volts) in the P-N-junction test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. A zener diode PN junction indirectly indicates a LED-a
On the motherboard EAX64910001 (1.0) - EBR75084309 4162, in case of a malfunction, you should first check the operation of all the stabilizers and power converters of the microcircuits, and also, if necessary, update the software (software).
In some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - CPU: LGE2111A-T8, Nand: H27U1G8F2BTR, DDR: K4B1G1646G-BCK0, SPI: 25Q80 with new or obviously working ones. In cases where BGA technologies are used, defects are usually localized by the heating method.
If there is no reception of television channels, but the TV is working properly from external devices, first of all you need to check the power supply of the TDSS-G101D tuner and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Attention! Users and owners of 42LS345T TVs who do not have the appropriate qualifications, knowledge and experience are strongly advised against self-repair attempts in order to avoid negative consequences that could lead to complete non-repairability of the device.
SCHEMATIC DIAGRAM ----------> LG CHASSIS: LD21C; MODEL: 42LS3450/345S/345T, 42LS3450/345S/345T-ZA
The appearance of the MainBoard EAX64910001 is shown in the figure below:
EAX64910001
EAX64910001 can be used in TVs:
LG 32LS340T (Panel LC320DXN), LG 32LS3510-ZB (Panel LC320EXN SEA2), LG 42CS460 (Panel LC420WUE (SC)(A3)), LG 32LS350T ZA (Panel T320XVN01.1), LG 42LS345T (Panel HC420DUN-SLCP1 11XX), LG 32CS465 ZA (Panel LC320WXN (SC)(A4)), LG 32LS345T (Panel 331537561 KENMOS 1365X768).
The appearance of the power supply
Main features of the device LG 42LS345T:
Installed matrix (LED-panel) HC420DUN-SLCP1 11XX.
The matrix control uses the Timing Controller (T-CON) 6870C-0401C.
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 MDD5N40 type are used.
The necessary supply voltages for all nodes of the LG 42LS345T TV are generated by the EAX64770201 power supply module or its analogs using SC1S311 microcircuits and power switches of the MDF10N65F type.
MainBoard - the main board (motherboard) is an EAX64910001 module using CPU chips: LGE2111A-T8, Nand: H27U1G8F2BTR, DDR: K4B1G1646G-BCK0, SPI: 25Q80 and others.
The TDSS-G101D tuner provides TV reception and channel tuning.