Super Noob, First AV restoration project. Sansui g5700 with no output transistor.

[jsolorza]

Hello everyone! I have been making the rounds through theses forums and I feel as I have a good base now. I have recognized some of the Sansui All Stars like ghazzer so hoping for an All Star appearance.
Disclamer, I have worked on electronics at work I am currently one semester from graduating with a physics and electrical engineering degree, so I know a little something about electronics. I currently build prototypes and fix power boards and other electronics at my current job so I am handy with a soldering iron.

I bought the receiver in my current profile picture. The lights are working however I bought it knowing it blew an output transistor. I assume that there will be some other component failures, most likely some resistors and perhaps diodes. The output transistor has been removed and I will have it in my hands in a few days.

My questions are the following. I have downloaded the schematic and service manual as well as read through some forums on here. But I would be lying if I said I knew where these bad boys are located. I believe They are TR-601 and TR-602 on the F-2981(l) & F-3093(R) boards. I have included the Picture of the schematic below. My main problem is that I do not really know what this board looks like or where it might be. I have included pictures of the schematics below as well as some from the MVP ghazzer on the boards. I guess my main question is am I handling the diagnostics right in this scenario? I know there are two boards that should be somewhat similar handling these 4 transistors. Should I be on the lookout for some common problems leading to this transistor blowing? I really want to learn how to apply my skills to old AV equipment. An I do not want to ruin such a beauty of a receiver with my novice skillz.

I will update pictures once I have it in hand it was shipped this morning from a couple hours away. I bought off an older gentlemen who couldn't work on it anymore due to his eyesight failing and he was having a hard time parting ways with it. I would really love to due this and him some justice .

Thanks in advance for any help and sorry for violating any posting rules on the forum it is my first post.

 

[GrisPato]

I do not have experience with this model but I dare to assume they are residing somewhere on a heatsink. Think they are located at the back of the receiver, with the cooling ribs.

 

[Tom B]

Yes those transistors are screwed to the heatsink, and soldered to small boards that have a few other components on them. The free service manual from HFE is not good definition so hard to see where those small boards are.
Assume though that if you have bad outputs you will have other components bad on the main amp F2980 board, as well as possible bad emitter resistors, and bias diode on that small board where the outputs are mounted.

 

[jsolorza]

I was so anxious to start that I got ahead of myself. I Appreciate the help. I finally have it in hand and they were pretty easy to locate with your help. I already ordered the first few needed parts for visual inspection and I will be diving in to this bad boy after my exams as my much needed leisure time. In afternoon of checking components and cleaning is in order. I assume the transistor blew because I can tell it was replaced and someone did a horrible job. They might have ruined a board with a hack soldering job; but e-bay is always there waiting for me and I don't mind beginning my back up parts catalog.