REPAIRING AND NOT THROWING AWAY

REPAIRING AND NOT THROWING AWAY

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and technical information about Service Modes, Circuit Diagrams, Firmware Update procedure, Disassemble procedure, Universal remote control set-up codes, Troubleshooting and more....

If you go into the profession, you will obtain or have access to a variety of tech tips databases HERE IT IS Master Electronics Repair !.

These are an excellent investment where the saying: 'time-is-money' rules. However, to learn, you need to develop a general troubleshooting approach - a logical, methodical, method of narrowing down the problem. A tech tip database might suggest: 'Replace C536' for a particular symptom. This is good advice for a specific problem on one model. However, what you really want to understand is why C536 was the cause and how to pinpoint the culprit in general even if you don't have a service manual or schematic and your tech tip database doesn't have an entry for your sick TV or VCR.

While schematics are nice, you won't always have them or be able to justify the purchase for a one-of repair. Therefore, in many cases, some reverse engineering will be necessary. The time will be well spent since even if you don't see another instance of the same model in your entire lifetime, you will have learned something in the process that can be applied to other equipment problems.
As always, when you get stuck, checking out a tech-tips database may quickly identify your problem and solution.In that case, you can greatly simplify your troubleshooting or at least confirm a diagnosis before ordering parts.

Happy repairing!
Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

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..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

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Wednesday, 26 February 2020

REPAIR / SERVICING TV LG 42LB650V

Technical description and composition of the LG 42LB650V TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 42LB650V
Chassis / Version: LD42B
Panel: LC420DUH (FG) (P2)
LED backlight: Direct 3.0_42inch_Rev7_A-TYPE_131202 / B-TYPE_131202
LED driver (backlight): integrated into PSU; 208V 250mA
PWM LED driver: BD9486F
Power Supply (PSU): EAX65423701 (2.0)
PWM Power: MAP8800 (PFC), FA6A01N (PWM resonant)
MainBoard: EAX65384004 (1.5)
IC MainBoard: CPU: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAI
Tuner: TDJM-G101D EBL61400501
Control: AKB73756565; WiFi: 2703H-LGSBW41, BEJLGSBW41
Specifications 42LB650V
LG 42LB650V
General repair guidelines for TV LCD LED
An external examination of the external and internal elements should be carried out in a timely manner before the start of operations for their dismantling. Visible damage to elements can sometimes indicate the direction of the search for a defect even before the necessary measurements are taken. Experienced repairmen are often aware of the causes of the defect and possible consequences, for example, from ring cracks in the soldered terminals of the elements, as well as from swollen capacitors or resistors burnt to coal dust and other external signs of certain malfunctions.
If the LG 42LB650V 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 EAX65423701 (2.0) power supply module. In some cases, only the processor power regulator may be faulty. When diagnosing and repairing the power supply, after replacing the swollen capacitors of the filters of the secondary rectifiers (if any), you must first check the mains fuse. When it is broken, the power elements of transistors and rectifier bridge diodes should be checked for avalanche (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, when you turn on the TV, the image appears and immediately disappears, or is missing initially when you turn on, but the sound has other functions that work, there is a high probability of a malfunction of the LED driver (LC420DUH (FG) (P2) panel LED backlight power converter).
A malfunction in the backlight circuits often occurs due to an open in the power circuit of the LED lines. It requires disassembling the panel and checking the LEDs themselves, the rations of their terminals, as well as the reliability of the connections in the connectors and rations of the terminals.
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 LED will light up slightly.
On the EAX65384004 (1.5) motherboard, 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).
When repairing an MB board, you need to check its CPU components: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAI. Defective items should be replaced. If BGA chips are installed, their malfunction is usually localized by heating.
Before replacing the TDJM-G101D EBL61400501 tuner, if there is no channel setting, you must first check the software and the supply voltage at its terminals.
Remember! Attempts to self-repair by users of the LG 42LB650V TV without the appropriate qualifications and the necessary experience can lead to serious negative consequences!
schematic diagram ------------>  LG CHASSIS LD42B MODEL: 42LB65** 42LB65**-Z*.

User Manual  diagram ------------>  WiFi  LG Wi-Fi Module LGSBW41
 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.


More details on this page



 The appearance of the MainBoard EAX65384004 is shown in the figure below:
EAX65384004
EAX65384004 can be used in TVs:
LG 32LB650V ZE (Panel LC320DUH (FG)(P2)), LG 47LB650V ZE (Panel LC470DUH (FG) (P2)), LG 42LB650V (Panel LC420DUH (FG)(P2)), LG 42LB671V ZF (Panel LC420DUH (PG) (F1)), LG 47LB671V (Panel LC470DUH (PG)(F1)), LG 42LB653V ZK (Panel LC420DUH (FG)(P1)), LG 42LB720V (Panel LC420DUH (PG)(F1)), LG 42LB658V (Panel LC420DUH (FG)(P2)), LG 47LB677V (Panel LC470DUH (FG)(F1)), LG 42LB679V (Panel LC420DUH (PG)(F1)), LG 47LB653V (Panel LC470DUH (FG)(P1)), LG 32LB653V (Panel LC320DUH( FG)(P1)), LG 42LB690V (Panel LC420DUH (PG)(F1)), LG 55LB630V (Panel LC550DUH).
PSU Advanced
The 42LB650V model uses the EAX65423701 power supply unit using the PFC (Power Factor Correction) node - an active filter of the highest harmonics of the current consumption. In fact, this is a boost converter based on the MAP8800 PWM controller, which eliminates the charge current of the electrolytic capacitor of the rectifier filter directly from the network through open diodes, when its charging current is determined by its reactance.
As a result of the operation of the converter, the envelope of the high-frequency pulses of the input current of the converter will repeat the shape and phase of the input voltage. The health of the PFC node can be indirectly judged by the presence of an increased constant voltage (about + 380V) on the capacitor of the rectifier network in operating mode.
The appearance of the power supply
Main features of the device LG 42LB650V:
Installed matrix (LED-panel) LC420DUH (FG) (P2).
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the BD9486F PWM controller.
The necessary supply voltages for all nodes of the LG 42LB650V TV are generated by the EAX65423701 power module or its analogs using MAP8800 (PFC), FA6A01N (PWM resonant) microcircuits.
MainBoard - the main board (motherboard) is an EAX65384004 module, using CPU chips: LG1311; DRAM: H5TQ4G63AFR-PBC; EEPROM: AT24C256C, EMMC: THGBMAG6A2JBAI and others.
Tuner TDJM-G101D EBL61400501 provides the reception of television programs and tuning to channels.
Information from an alternative source:
LG 42LB650V Chassis LD42B
Panel Type (Matrix): LC420DUH (FG) (P2)
Motherboard: EAX65384004 (1.5), Tuner: TDJM-G101D EBL61400501, WIFI / BT: LGSBW41, IR: EBR78480603
PSU: EAX65423701 (2.0)
Additional technical information about the panel:
Brand: LG Display
Model: LC420DUH-FGP2
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 (2H)
Brightness: 300 cd / m²
Contrast Ratio: 1200: 1
Display Colors: 16.7M (8-bit), CIE1931 68%
Response Time: 6/8 (Tr / Td)
Frequency: 120Hz
Lamp Type: WLED Without Driver
Signal Interface: EPI, 100 pins
Voltage: 12.0V
Posted By: FRANK at 07:10
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