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, 4 March 2020

REPAIR / SERVICING TV LG 49UH676V

Technical description and composition of the LG 49UH676V TV, panel type and applicable modules. The composition of the modules.
LG LED
Model: 49UH676V
Chassis / Version: RD63J51EK4
Panel: LC490DGG (FJ) (M5)
LED backlight: 6916L-2551A (UHD) LEFT 1, 6916L-2452A (UHD) LEFT 2, 6916L-2552A (UHD) RIGHT 1, 6916L-2453A (UHD) RIGHT 2
LED driver (backlight): integrated into PSU
Power Supply (PSU): EAX66793401 (1.6) EAY64229801 PLDH-L507A 3PCR01338A
MainBoard: EAX66804605 (1.1) RD63J51EK4 EBT64102516 EBT64202216 GN6DF113MW
Tuner: TDJN-G301D
Control: IR: SERONICS LH60_V1.0 20151208, WiFi: BEJLGSBWAC61 pn EAT63153401
Specifications 49UH676V
LG 49UH676V
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 49UH676V TV does not turn on, does not respond to the remote control and the control panel buttons, the indicators do not light or flash.
With such manifestations, the EAX66793401 power module usually fails. It is necessary to measure its secondary output voltages, and if they are absent, check the power switches and rectifier diodes in the converters for a 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.
Breakdown of power switches (MosFet) in pulsed sources is sometimes caused by malfunctions of other circuit elements, for example, in circuits supplying a PWM controller, frequency-setting or damper ones, as well as in negative feedback (OOS) stabilization circuits. PWM controllers (PWM), if they do not have visible damage to the case and open short circuit between the terminals, are usually checked by replacement.
- 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 some of these cases, the malfunction is caused by the lack of a backlight display. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
To check the LED strips, to open all the transitions of the LEDs, several tens of volts or more are needed, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED transitions in forward bias, you can sometimes detect the presence of a PN junction of the protective zener diode by connecting the probes in the opposite direction. If the zener diode is broken or broken in short-circuit, then the LED is faulty and needs to be replaced.
- The indicator on the front panel blinks, the TV does not turn on in operating mode, it does not respond to the remote control.
Repair or diagnostics of the EAX66804605 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).
If there is no reception of television channels, but the TV is working properly from external devices, first of all it is necessary to check the voltage of the tuner TDJN-G301D and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
TV users and owners need to remember that attempts to self-repair a LG 49UH676V TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!




The appearance of the MainBoard EAX66804605 is shown in the figure below:
EAX66804605
The appearance of the power supply
Main features of the device LG 49UH676V:
Installed matrix (LED-panel) LC490DGG (FJ) (M5).
To power the backlight LEDs, a converter is used, combined with a power supply.
The formation of the necessary supply voltages for all nodes of the LG 49UH676V TV is carried out by the EAX66793401 power module, or its analogues.
MainBoard - the main board (motherboard) is an EAX66804605 module.
The TDJN-G301D tuner provides TV reception and channel tuning.


Posted By: FRANK at 06:44
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