View Full Version : Sansui AU-7900 - damaged relay?

07-11-2013, 01:34 PM
I've just unearthed my late dad's Sansui AU-7900 amplifier from one of our family crates. It still has perfect cosmetic condition. Dad wrapped it in thick cloth to keep it from impact or scratches. I then tested it with a pair of Phillips speakers and my laptop.

(1) The first time I turned off the amp, the power indicator light is on, but no sound was heard from the amp.

(2) Then I turned off the amp, but I left the power plugged. I left it about an hour (because I was busy with something else), then I turned it on again. This time, I heard a distinctive "click" sound. And when I tested it, the amplifier works! Not only it works, but it works perfectly. The sound was still perfect, clean, and quite detailed despite the mediocre Phillips speakers I was using.

(3) I listened to the amplifier about an hour, enjoying various kind of music with it. Then I turned off the amplifier and went to dinner.

(4) after I finished my dinner, I turned on the amp again. This time, I didn't hear the "click" sound (just like the first time I turned on the amplifier). And again, the amplifier made no sound. No click, no sound.

I suspect the relay has been damaged, probably because of old age. I also believe that the "sound part" of the amplifier is still perfect, because the sound plays perfect when the amp works (ie clicking sound after I turn it on).

But can someone confirm this? I'm fairly new in electronics, so I think I may be wrong.