Sansui AU517 Spitting at Startup

[avantbored]

Hi all.

I'm picking up my AU517 from a tech who doesn't have time on his bench to work on it.

The problem: Spitting noise on start up. Lasts about 10 or 15 seconds. Rapid at the beginning, then tempers toward the end.

This thing has been worked on: boards recapped. I did not take them out to look at the extent of the work, but the glue has been removed.

Seeking some ballpark ideas while I find another tech who has the time to work on it. Noisy transistors? What do we think?

Thank you all for your time.

 

[Robisme]

Most likely loaded with 2SA750 transistors. They are thought by some, myself included, to go noisy.

Rob

 

[Sui-Yogi]

Most likely loaded with 2SA750 transistors. They are thought by some, myself included, to go noisy.

Rob

That or the “fuse resistors” …. I would put my bet to the fuse resistors .
In any case, replacing the above transistors and this resistors is the way to go .

 

[avantbored]

Thanks for the input! I will ask my tech to do this.

Strikes me now it's been a minute since I've cleaned it, and I noticed some scratchiness on the Balance pot. It made me think that perhaps this issue could be a pot/switch? I don't know if I cleaned that pre-power switch at the rear since I've owned it.

 

[Sui-Yogi]

Back switch “connected/separated “ is a “must to do” too , before you go further into troubleshooting.