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 55SL8500

Technical description and composition of the LG 55SL8500 TV, panel type and applicable modules. The composition of the modules.
LG
Model: 55SL8500
Chassis / Version: LD91K
Panel: LC550WUD (SB) (04)
Inverter (backlight): integrated into PSU
Power Supply (PSU): LGP55-09S EAY58476101
PWM Power: R2A20112, L6599, VIPer27H
Mainboard: EAX60890804
IC MainBoard: 25X32VSIG
Technical Specifications 55SL8500
LG 55SL8500
General recommendations for repairing TV LCD
Possible malfunctions
- LG 55SL8500 does not turn on, the indicators on the front panel do not light up and do not blink. The TV does not respond to the control buttons and the remote control.
In some of these cases, a malfunction is detected in the LGP55-09S power supply module. Then it is necessary to measure its output voltages and, in case of their complete or partial absence, it is necessary to check the serviceability of power switches and rectifier diodes of the converters for a possible short circuit.
In case of breakdowns of diodes in the secondary circuits, the converter can operate in emergency short circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM circuits (PWM) R2A20112, L6599, VIPer27H are usually checked by replacing with new ones, or obviously working.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
The defect can be caused by problems in the nodes or elements of the backlight of the display, or in the power supply of the lamps or inverter. If all the electrolytic capacitors of the filter according to the power supply of the inverter are working, make sure that the lamps are working, then you need to check the converter keys and the secondary windings of the transformers.
Sometimes, for diagnostic purposes, it is necessary to disable the inverter protection. In such cases, special care must be taken when working, and the protection circuits should be restored immediately after the repair is completed.
- 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 EAX60890804 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). In cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its 25X32VSIG chips and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
TV users and owners need to remember that attempts to self-repair a LG 55SL8500 TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!





The appearance of the MainBoard EAX60890804 is shown in the figure below:
EAX60890804
Main features of the device LG 55SL8500:
Installed matrix (LCD panel) LC550WUD (SB) (04).
To power the backlight, a converter is used, combined with a power supply.
The formation of the necessary supply voltages for all nodes of the LG 55SL8500 TV is carried out by the LGP55-09S power module, or its analogs with the use of R2A20112, L6599, VIPer27H microcircuits.
MainBoard - the main board (motherboard) is an EAX60890804 module, using 25X32VSIG chips and others.
Posted By: FRANK at 08:17
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