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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Tuesday, 26 February 2019

HOW TO TROUBLESHOOT CHINESE TV KIT USING LA-76931 AS MCU+DECODER

HOW TO TROUBLESHOOT CHINESE TV KIT USING _ LA-76931 AS MCU+DECODER



     If you have remote control [DGT-5AM3], it has a hidden key (a hole on it) by which you can activate the service mode by it.  To Exit from service mode too, you can use this hidden key.


SERVICE FLOW CHART


POWER SUPPLY
Check input voltage => Check voltage of C910 anode => Check pin number 3 of N901 => Check V910 => Check output voltage of T901 secondary coil => Check voltage of N904, N905 Pin-3 [5V] and N903 pin-3[9v] => Check voltage of N103 Pin 8,31,32,35,36,43,55 [5V], and pin 11,19 [8v] => check voltage of N602 pin 8 [+5V].


AUDIO CIRCUIT


Check supply to audio power amp circuit => Check input audio signal.


HORIZONTAL CIRCUIT


Check voltage of T402-pin 3 [110V] => Check voltage of N103 pin-19[+9V] => Check frequency at V401 base => Check wave form of V402-collector => Cehck output voltage of T402 coil => Check wave form of T402 pin-8.


VERTICAL CIRCUIT


Check voltage of N440 pin-2[+25V] and pin-7[+9V] => check voltage of N103 pin-19[+9V] => check waveform of N103 pin-17 => check waveform of N440 pin-1 => check waveform of N440 pin-5.


MCU CIRCUIT


Check voltage of N103 pin-31,32(+5V) => Check waveform of N103 pin-33