sansui won't click

[clippking]

Hope someone can help. I picked up a Sansui AU 7700 amp at a garage sale. Awsome deal, amp, Sansui tuner and kenwood tape deck for $5. Set it up and it worked fine. Next time I went to use it nothing. Amp light comes on has outlets on the back have power, but no click. Came back a few days later turn it on amp clicks and is fine. Today gone again. 6 amp fuse looks fine. Where do I go next?

Sorry if this is a common question, I am new and amateur, but I really like the amp and hope I can fix it. It also sounded great when it was working.

Thanks for any suggestions

 

[lanchile]

it can be many things...check for bad caps or relays. without troubleshooting it is not easy.🙄

 

[bob91343]

Measure the output voltage of each amplifier to see how close to zero volts it is. Check the service manual and adjust if necessary. Watch to see how stable it is; if it drifts too far, the protection circuitry will disconnect the speakers.

 

[Mooly]

Might be nothing more than dry joints somewhere... disconnect the speakers and gently tap and apply pressure around the PCB's with a plastic tool and see if the relay clicks in and out.
Favourites are any components that run hot, resistors, transistors etc. Just look carefully at all the soldering and tap around.

 

[TonyTecson]

most likely output offset in one channel....

 

[DigitalJunkie]

I had a 5500? with a similar issue.It would randomly disconnect,or not click when power was turned on.After some more investigation,I discovered the bias and offset wouldn't sit still because of leaky electrolytic caps.New caps fixed it right up,and new trimpots didn't hurt either. After that it was rock-steady. 🙂

 

[TonyTecson]

yes, re-capping won't be a bad idea.....

 

[east electronics]

recaping at this age is a simple fact .... you need to replace all ...and all means all ...

some more info regrading the procedure can be found here http://www.diyaudio.com/forums/solid-state/136261-vintage-amplifier-repair-upgrade-manual.html