[Gvt1911]

Trying to help out a friend with an older Adcom 5400 amp...One channel is not working, get a low, distorted /sputter type sound coming from it...All voltages coming from power supply are good and board is getting juice...Of course everything looks fine and he claims unit was working 3 years ago before being put into storage...
Any ideas as to where to look? Hate to send unit back to Adcom for something minor...
Thanks 

[nodiak]

Try replacing all the fuses inside, cheap and easy. This was all my Adcom 555 needed with a dead channel. Tho didn't have sputtering noises. Do a dust clean up while it's open, and unplugged of course. Careful not to bump anything out of position in there.
Don

[drphoto]

Agree w/ nodiak. I have two 555's and that's the classic sign of blown internal fuses. Often caused by turning on preamp after amps are powered. Make sure those caps are drained before you go poking around in there. I used to pry 'em loose w/ a wooden chopstick just to make sure.

[Gvt1911]

Forgot to advise that amp was cleaned inside with compressed air and all fuses were tested and are good...

[drphoto]

Ouch....dunno at this point. Maybe replace fuses even if they test good? Used Adcom amps are pretty cheap. I'm one loathe to throw away stuff, but it might not be worth fixing if a blown ouput transitor. I figure mine or worth a couple hundred bucks at best. I'm saving them for some possible use in an HT system down the road.

[Doublej]

If there are any relays (power on, shorting protection) check those. They have been known to fail in the manner you have indicated.


Also consider asking these guys

http://www.fixya.com/support/

and looking for a Adcom Yahoo group if it's worth your time to attempt to get an answer.

[mjosef]

There are several threads on troubleshooting Adcom amps over at DIY Audio forum, a couple of the guys over there are/were Adcom authorized techs:
http://www.diyaudio.com/forums/forumdisplay.php?s=&forumid=4