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All static in left channel

So I left it on for about 2 hours. Came back and things seemed good. Still if you pushed "lightly" on any of the relays you could get the bad signal again.

So here is my logic and what I did:

The main PCB is mounted toward the bottom of the amp so all the component are facing the bottom of the amp. The solder joints facing upward. The bottom cover of the amp when installed is only about 1/8" or 3/16" away from the plastic relay covers. So my thoughts are in shipping (despite how great it was packed), if this thing took a good slam it is possible the relays got a bump / slam too. So with that thought and the fact that when light pressure is applied to the relays I'm figuring possible fractured solder joints.

I was able to the the circuit board out far enough to expose the solder side, but could not get close enough with a magnifying glass to really inspect. So I just went ahead and reheated each connection on each relay. I only hit each connection 1-2 seconds just enough to re-puddle the solder.

Turned it back on and still had similar problem but not near as bad. So one more time resoldered this time just coating my iron tip with solder. Turned it on again and so far no problem. I'm letting it cool down and will restart again in a while; I'm a skeptic at this point, but very hopeful.

Left channel still seems a little more quite than the right, but isn't that typical of most recording. I'm paying attention to things I hadn't before, so my mind is mush.

Does this make sense and does any think this could have been the problem? I'll update you shortly.
 
One other thing. There are 2 speaker relays, one for A and one for B. Both channels exhibit the same condition (left only). So I started to eliminate the relays as a potential problem. However I also doubt the only the left solder joints were fractured too. Since I don't know anything about the circuitry I don't know what does or doesn't make sense.

1 hour later....

Turned everything back on and yes it still is working. Pushing lightly on all relays and no change. Woo Hoo!

Reassembled and tested again after each part was put back on. Still works Woo Hoo again.

Yes the left channel was quieter than the right. I brilliantly diagnosed this one myself...the left input gain on the back of the amp had gotten turned during all this moving around. Both channels fine.

Lastly... once the bottom was put back on I confirmed my suspicion. If you put mild pressure on the center of the bottom cover, the relays are the first thing to stop it. So in it's long journey I'm sure there was someone tired and not in the mood to lift the 50lb box and slammed it a time or 2. Just a guess, but it works for now.
 
Oh yea, thanks to all who commented. There is NO way I would have even know to take off the bottom cover and look for any of this stuff. You all made my day!!
 
Hope all is still working well for you. Looks like old1625 had it right then with the fractured solder connections, huh?

Now you have a working amp and know a little bit more about the insides :)
 
Yes old1625 sounds like he has looked at a few things. Nothing like experience. But thanks to all of you electronic guys for helping the village idiot out of a jamb.
 
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