Monday 24 February 2020

REPAIR / SERVICING TV LG 42LB563V

Technical description and composition of the LG 42LB563V TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 42LB563V
Chassis / Version: LC43B / LD43B / LB43T
Panel: LC420DUE (FG) (A3)
LED backlight: 6916L-1956A / 1957A - LG lnnotek DRT 3.0 42_A / B type Rev01 6916L-1709A / 1710A
T-CON: 6870C-0480A
LED driver (backlight): integrated into PSU; 208V 250mA
PWM LED driver: BD9486F
MOSFET LED driver: MDD3752, 4NF20
Power Supply (PSU): EAX65423701 (2.0) LGP3942-14PL1
PWM Power: MAP8800 (PFC), FA6A01N (PWM resonant)
MOSFET Power: TK7P60W
MainBoard: EAX65388005 (1.0)
IC MainBoard: CPU: LGE2132; H27U1G8F2CTR, 74LCX244, TPS65282, 25Q80BVSIG, TAS5733, A8303
Tuner: TDJM-G101D
Control: AKB73715679
Specifications 42LB563V
LG 42LB563V
General repair guidelines for TV LCD LED
Repair of electronic devices, including the TV LG 42LB563V, it is advisable to start with an external examination of its external and internal elements. A visible physical change in some components can sometimes suggest a further troubleshooting direction. Electrolytic capacitors of filters with a swollen casing, as well as ring cracks formed in the soldered leads of heating elements, or a layer of coal on burnt resistors sometimes tell the repairman the causes of the malfunction and possible consequences.
In the case when the 42LB563V does not turn on, does not respond to the remote control and the front panel buttons, does not blink light bulbs and does not show any signs of operability, the EAX65423701 (2.0) LGP3942-14PL1 power supply module is probably defective in this case. 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.
As a rule, the keys in switching power supplies (SMPS) are reliable enough and rarely fail for no reason to be looked for by checking other components of the circuit - electrolytic capacitors, resistors and semiconductor elements of the primary circuit. The PWM chip is verified by replacing it with a known good one.
In cases where the LG 42LB563V TV has lost its image, and the sound is there and all the other functions are operational, there is a possibility of a malfunction of the LED driver (converter for powering the backlight LEDs of the LC420DUE (FG) panel (A3)). When you turn on the TV, the image may appear briefly and disappear immediately. It must be borne in mind that with such manifestations the LEDs themselves also fail.
In case of breaks in the LED circuit, a complete disassembly of the panel is required, the LEDs are checked for an open circuit, as well as the reliability of the connections in the connectors and rations of the terminals.
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes.
In cases of attempts to repair the motherboard EAX65388005 (1.0), it is necessary to check the operability of the linear stabilizers and power converters of its microcircuits and, if possible, update the software (software). BGA chips can sometimes be diagnosed with local heating.
In the absence of tuning to local television channels, you should make sure that the software is correct, as well as the presence of supply voltages at the terminals of the TDJM-G101D tuner.
  • Once again, remind users! Attempts to self-repair the LG 42LB563V TV without the appropriate qualifications and experience can lead to its complete non-repairability!


Backlight Current Limit:
In televisions with power supplies LGP3942-14PL1 (EAX65423701), the backlight current sensor - the resistor block R811-R818 consists of four pairs of 4.3 Ohm each. You can reduce the backlight current by 25% by removing one pair of resistors.

Schematic diagram ------------>  CHASSIS : LD43B/LD44B MODEL : 42LB56** 42LB56**-Z*




 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)).
PSU Advanced
On the 42LB563V TV, the EAX65423701 power module is installed using the PFC (Power Factor Correction) scheme acting as an active filter to eliminate the higher harmonic components of the current consumption. The boost converter based on the MAP8800 PWM controller does not allow the electrolytic capacitor of the input rectifier filter to be connected directly to the network directly through open diodes, when the value of the charge current determines its reactance (about 15-30 ohms at a frequency of 50 Hz). As a result of the conversion, the charging current of the capacitor will be determined in such a way that the envelope of the high-frequency pulses of the input current will repeat the phase and shape of the sine wave of the input voltage. The health check of the PFC unit is carried out by measuring the DC voltage on the capacitor of the rectifier network. In operating mode, it should be around 380V, in standby approximately 300V.
The appearance of the power supply
Main features of the device LG 42LB563V:
Installed matrix (LED-panel) LC420DUE (FG) (A3).
The matrix control uses the Timing Controller (T-CON) 6870C-0480A.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the BD9486F PWM controller. As power elements of the LED driver, keys of the MDD3752, 4NF20 type are used.
The necessary supply voltages for all nodes of the LG 42LB563V TV are generated by the EAX65423701 power module or its analogs using MAP8800 (PFC), FA6A01N (PWM resonant) microcircuits and TK7P60W power switches.
MainBoard - the main board (motherboard) is an EAX65388005 module, using CPU chips: LGE2132; H27U1G8F2CTR, 74LCX244, TPS65282, 25Q80BVSIG, TAS5733, A8303 and others.
The TDJM-G101D tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC420DUE-FGA3
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: IPS, Normally Black, Transmissive
Active Area: 927.94x521.96 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