Hi guys, I have a broken AVR which is working in 3 phase 50Hz 250 KVA 1500 RPM synchronous generator.

I have trouble to find out the IC and the transistor type.

Any suggestion, ill persuade any kind of help to fix this problem?

 

Is there a part number on the IC?

 

no, someone has erase it...

 

That is too bad. Manufacturers sometimes do that to make repairs almost impossible - you have to go back to them and get a new board.

 

Some programmers are able to identify chips. Try to do it.

 

And yet they socketed them. Stupid.

 

We used to see that all the time. If you get lucky and get the light just right, you can make out the number.

The way it's done now is to contract for an IC that is slightly different from the industry standard so the details become IP and therefore secret. That way, the numbers are absolutely useless. When they remove the numbers, the IC is a standard one, and the function may sometimes be derived from the function and what goes on at the pins.

 

And yet they socketed them. Stupid.

I have an old 5-1/2 digit DVM I bought from eBay which is the physical size of the original IBM PC and every IC(50 of them) inside is socketed.

As I understand from the seller, the meter was once used in MOD.

Like you, I was skeptical. Finally I have had a chance to ask the meter designer in email why every IC is socketed?

His answer was that if proper socket is used no problem/fault whatsoever was ever encountered as a direct relation to the sockets. Socketed IC make troubleshooting a breeze and they can usually return the repaired meter to the customer within a day.