Technical description and composition of the LG 39LB650V TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 39LB650V
Chassis / Version: LD42B
Panel: T390HVJ01.2
LED backlight: LG lnnotek DRT 3.0 39_A / B type Rev01_140107
T-CON: T420HVD03.1, 42T33-C02
LED driver (backlight): integrated into PSU; 208V 250mA
PWM LED driver: BD9486F
MOSFET LED driver: MDD3752, 4NF20
Power Supply (PSU): EAX65423701 (1.9) - LGP3942-14PL1
PWM Power: MAP8800 (PFC), FA6A01N (PWM resonant)
MOSFET Power: TK7P60W
MainBoard: EAX65384003 (1.2)
IC MainBoard: H5TQ2G63FFR, H5TQ4G63AFR, SAA37219517M, SAA36900716, Audio: NTP7514, TPS65175B, TPA6138, SN1302001, RTL8201F, TPS53513
Tuner: TDJM-G101D
Control: AKB73756565; WiFi: 2703H-LGSBW41, BEJLGSBW41
Specifications 39LB650V
LG 39LB650V
General repair guidelines for TV LCD LED
In the absence of any signs of operability, when the LG 39LB650V does not turn on and does not signal anything with the control lights on the panel, there is a possibility of a malfunction of the power module EAX65423701 (1.9) - LGP3942-14PL1 of the TV. 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.
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 (power converter for the T390HVJ01.2 xxxxG panel illumination unit).
A malfunction in the backlight circuits often occurs due to an open in the power circuit of the LED lines. It is necessary to disassemble the panel and check the LEDs themselves, the soldering of their conclusions, as well as the reliability of the connections in the connectors and the soldering of the conclusions of the connectors.
It should be remembered that it is not possible to determine the open circuit in the LED lines without disassembling the panels with a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required. Then it is necessary to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow you to open the LED in the forward direction or dual LEd are used, then the PN junction of the emergency zener diode can indirectly serve as a health indicator. In case of LED-a failure, the zener diode PN junction will either be cut off or broken into short-circuit.
Repair of the EAX65384003 (1.2) 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.
If it is not possible to replace the MB (SSB) card, you need to check the health of its elements - H5TQ2G63FFR, H5TQ4G63AFR, SAA37219517M, SAA36900716, Audio: NTP7514, TPS65175B, TPA6138, SN1302001, RTL8201F, TPS53513. Defective components should be replaced.
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.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repair only to professionals with sufficient experience in the field of electronic equipment repair.
schematic diagram -------------> LG CHASSIS LD42B; MODEL 39LB650V, 39LB650V-ZE/ZN.
User Manual schematic diagram -------------> WiFi LG Wi-Fi Module LGSBW41
The appearance of the MainBoard EAX65384003 is shown in the figure below:EAX65384003
EAX65384003 can be used in TVs:
LG 47LB650V ZE (Panel LC470DUH (FG) (P2)), LG 42LB631V ZL (Panel LC420DUH (FG) (A1)), LG 39LB650V (Panel T390HVJ01.2), LG 55LB673V ZB (Panel LC550DUH (PG)(F1)), LG 47LB677V (Panel LC470DUH (FG)(F1)), LG 42LB673V (Panel LC420DUH (PG)(F1)), LG 47LB673V (Panel LC470DUH (PG)(F1)), LG 32LB652V 32LB652V-ZA.BRUWLDU (Panel LC320DUH (FG)(P2)), LG 50LB653V (Panel LC500DUH (FG)(P1)), LG 42LB652V 42LB652V-ZA.BRUWLJU (Panel LC420DUH (FG)(P2)), LG 55LB720V 55LB720V-ZG.BRUWLJU (Panel LC550DUH (PG)(F1)).
PSU Advanced
According to the conditions of compliance with modern world standards for household switching power supplies, the EAX65423701 module provides for the use of a Power Factor Correction unit. The PFC circuit is a flyback converter based on the MAP8800 PWM controller. The reactance of an electrolytic capacitor of a line filter at a frequency of 50-60 Hz is usually not more than 20-30 ohms and its charge directly from the network through open diodes could reach tens of amperes per pulse if no filtering were applied.
As a result of the PFC conversion, an increased voltage on the capacitor (about 380V) cannot directly open the rectifier diodes, on the anode of which the voltage will always be slightly less (about 300V) and then its charging current will always be limited by the elements of the PWM controller. As a result, the envelope of the high-frequency pulses of the consumed current will repeat the shape and phase of the input sinusoidal voltage. The presence of an increased voltage (+ 380V) on the network capacitor indicates the serviceability of the PFC node.
The appearance of the power supply
Main features of the device LG 39LB650V:
The matrix (LED panel) T390HVJ01.2 is installed.
The matrix control uses the Timing Controller (T-CON) T420HVD03.1.
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 39LB650V TV are generated by the EAX65423701 power supply module or its analogs using MAP8800 (PFC), FA6A01N (PWM resonant) microcircuits and TK7P60W power switches.
MainBoard - the main board (motherboard) is an EAX65384003 module, with the use of H5TQ2G63FFR, H5TQ4G63AFR, SAA37219517M, SAA36900716, Audio: NTP7514, TPS65175B, TPA6138, SN1302001, RTL8201F, TPS5.
The TDJM-G101D tuner provides television reception and channel tuning.