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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Thursday 27 February 2020

REPAIR / SERVICING TV LG 42LF560V

Technical description and composition of the LG 42LF560V TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 42LF560V
Chassis / Version: LC55H / LD55T / LB55T / LJ55T
Panel: LC420DUE (MG) (A3)
LED backlight: LG lnnotek DRT 3.0 42_A type / 42_B type Rev01 (01.01.07) - LED 6V
T-CON: 6870C-0480A
LED driver (backlight): integrated into PSU; 208V 235mA
PWM LED driver: LC5901
Power Supply (PSU): EAX66203001 (1.7) LGP3942D-15CH1
MainBoard: EAX66203805 (1.2) RD5NJ41EBV
IC MainBoard: CPU: LGE2134; NAND Flash: TC58NVG0S3HTA00; SPI Flash: MX25L8035EM2I; EEPROM: 24C256
Tuner: TDJM-G301D
Control: IR: EBR78480602
Specifications 42LF560V
LG 42LF560V
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 42LF560V TV does not turn on and does not show any signs of turning on, does not respond to the control buttons or to the remote control.
In such cases, the EAX66203001 power supply is usually faulty. Then we recommend that you measure its output voltages and, if they are absent, you should check the health of the power switches and rectifier diodes of the converters for a probable short circuit.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in emergency short-circuit mode without output voltages, and during short circuit in the elements of the primary circuit, the main fuse and, less often, the current sensor at the source of the key are most often cut off.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke the excess of maximum current or voltage values. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM), in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, but there is sound and reaction to commands from the remote control. Or the image appears immediately after turning on and disappears.
In most of these cases, a malfunction is detected in the nodes and backlight elements of the LED panel. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
When trying to detect a break in the LED lines, it should be taken into account that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
- 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 EAX66203805 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). When repairing an MB board, you need to check its CPU components: LGE2134; NAND Flash: TC58NVG0S3HTA00; SPI Flash: MX25L8035EM2I; EEPROM: 24C256. Defective items should be replaced. If chips with BGA soldering technology are used, a problem in its implementation is detected by the local heating of the chip.
Before changing the tuner TDJM-G301D, if it is not possible to tune to television channels, make sure that there are power supply voltages that must be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
It should be remembered! Attempts to self-repair the LG 42LF560V TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!
SCHEMATIC DIAGRAM --------->  LG 42LF560V Chassis LD55T. 42LF56** 42LF56*-Z*


 You can reduce the backlight current in televisions with LGP3942D-15CH1 power supplies (EAX66203001) by increasing the resistance of the current sensor. The nominal current in the LEDs is 250 mA. Current sensor - resistor R816 rated 3 Ohm. If you increase the rating to 4.3 Ohm, the current decreases to 175 mA.


 The appearance of the MainBoard EAX66203805 is shown in the figure below:
EAX66203805
EAX66203805 can be used in TVs:
LG 32LF564U (Panel LC320DXE (MG)(A3)), LG 42LF550V (Panel LC420DUE (MG)(A6)), LG 32LF560U ZB (Panel NC320DXN VSBP5 ), LG 42LF560V (Panel LC420DUE (MG)(A3)), LG 32LF562V (Panel NC320DUN-VBBP3 (EAJ63171201)), LG 32LF564V (Panel NC320DUN VBBP3), LG 32LF560V (Panel NC320DUN-VBBP3), LG 49LF620V 49LF620V-ZB (Panel LC490DUE (MG)(P2)), LG 42LF551C (Panel LC420DUE-MGA6).
The appearance of the power supply
Main features of the device LG 42LF560V:
Installed matrix (LED-panel) LC420DUE (MG) (A3).
The matrix control uses the Timing Controller (T-CON) 6870C-0480A.
To power the backlight LEDs, a converter is used, combined with the power supply, controlled by the LC5901 PWM controller.
The formation of the necessary supply voltages for all nodes of the LG 42LF560V TV is carried out by the EAX66203001 power module, or its analogues.
MainBoard - the main board (motherboard) is an EAX66203805 module, using CPU chips: LGE2134; NAND Flash: TC58NVG0S3HTA00; SPI Flash: MX25L8035EM2I; EEPROM: 24C256 and others.
The TDJM-G301D tuner provides TV reception and channel tuning.
Posted By: FRANK at 06:10
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