Technical description and composition of the LG 32LB628U TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 32LB628U 32LB628U-ZB.BRUWLDU
Chassis / Version: LD43B
Panel: LC320DXE (FG) (P2)
T-CON: 6870S-1578C
LED driver (backlight): integrated into PSU; 117V, 250mA
PWM LED driver: SSC1S311, A27RAW (sot-26)
MOSFET LED driver: STN4NF20L, STD11N65M5
Power Supply (PSU): LGP32-14PL1 EAX65391401 PLCD-L306A 3PCR00449D
PWM Power: NCP1251, NR134S (Step-Down)
MOSFET Power: KP8N65
MainBoard: EAX65388005
IC MainBoard: LGE2132 / A7MKM69C, H27U1G8F2CTR, 74LCX244, TPS65282, 25Q80BVSIG, TAS5733, A8303
Tuner: TDJM-G101D
Control: Remote: AKB73715694
Specifications 32LB628U
LG 32LB628U
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The LG 32LB628U 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.
In some of these cases, a malfunction is detected in the LGP32-14PL1 power supply module. It is necessary to measure its output voltages, and if they are absent (full or partial), you should check the operability of the power switches (KP8N65) of the converters and rectifier diodes for a possible short circuit.
In case of any breakdowns in the secondary circuits, the converter can operate in emergency short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key more often breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM chips NCP1251, NR134S (Step-Down) are usually checked by replacing with new ones, or obviously working.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
Usually in such cases, a malfunction is detected in the backlight nodes of the LED panel. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the LED line for breaks without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts will be required, and ideally, a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters, as a rule, light up a single 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as a health indicator. In faulty LEDs, the zener diode will either be cut off or broken into short-circuit.
- 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 EAX65388005 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). Board repair and replacement of LGE2132 / A7MKM69C, H27U1G8F2CTR, 74LCX244, TPS65282, 25Q80BVSIG, TAS5733, A8303 microcircuits are carried out with the necessary equipment, and the corresponding element base. Faults associated with the application of BGA processor soldering technologies can be localized by the heating method.
If a TDJM-G101D tuner is suspected of malfunction, first of all, it is necessary to verify the correctness of the software, as well as the presence of the necessary supply voltage levels and data exchange pulses with the processor via the I2C bus on the corresponding tuner pins.
Attention to users! Self-repair of the LG 32LB628U TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
Service manual and schematic diagram -----------------------> LG 32LB628U Chassis LD43B
You can reduce the backlight current in LG TVs with LGP32-14PL1 power supplies (EAX65391401) as follows. The current sensor consists of six resistors R816-R821 connected in parallel - 1 Ohm, 1 Ohm, 1 Ohm, 1 Ohm, 2 Ohm, 8.2 Ohm. The total resistance in this case will be 0.22 Ohm. If you remove one resistor 1 Ohm, the total resistance increases to 0.28 Ohm, the current decreases proportionally from 250 mA to about 190 mA.
More details on this page
The appearance of the MainBoard EAX65388005 is shown in the figure below:
EAX65388005
EAX65388005 can be used in TVs:
LG 32LB561U (Panel NC320DXN VSBP1), LG 42LB563V (Panel LC420DUE (FG)(A3)), LG 32LB565U ZQ (Panel LC320DXE (FG)(A3)), LG 42LB561V ZE (Panel LC420DUE (FG)(A3)), LG 49LB552V ZA (Panel LC490DUE (FG)(A6) ), LG 42LB565V (Panel LC420DUE (FG)(A3)), LG 32LB628U 32LB628U-ZB.BRUWLDU (Panel LC320DXE (FG)(P2)), LG 47LB561V-ZE 47LB561V (Panel LC470DUE( FG)(A3)).
The appearance of the power supply
Main features of the device LG 32LB628U:
Installed matrix (LED-panel) LC320DXE (FG) (P2).
The matrix control uses the Timing Controller (T-CON) 6870S-1578C.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by a PWM controller SSC1S311, A27RAW (sot-26). As power elements of the LED driver, keys of the STN4NF20L, STD11N65M5 type are used.
The necessary supply voltages for all nodes of the LG 32LB628U TV are generated by the LGP32-14PL1 power module, or its analogs using NCP1251, NR134S (Step-Down) microcircuits and KP8N65 type power switches.
MainBoard - the main board (motherboard) is an EAX65388005 module, using chips LGE2132 / A7MKM69C, H27U1G8F2CTR, 74LCX244, TPS65282, 25Q80BVSIG, TAS5733, A8303 and others.
The TDJM-G101D tuner provides television reception and channel tuning.