Left channel out (still causing trouble!)

[denti alligator]

No, no. I'm getting sound, but it's barely audible... fading, crunchy sounding.

But now I'm going crazy: I realized jiggling the cable in the L output that this made the sound go clean/crunchy, so I swopped cables, which would tell me whether the problem lies with the cable or the jack, right? Well, now both channels sound perfect. WTF?

 

[mcandmar]

Sounds like you found the issue, bad connection on the left output jack.  Possible its the cable, but switching the left/right cable around will confirm that for you.

 

[denti alligator]

It's the jack, I'm pretty sure. But I can't figure out what the problem is. When I press down on the plastic chassis right by the L output jack the sound comes in clear. What does that suggest?

 

[denti alligator]

So I loosed and re-tightened the jack. It now appears to be OK. Could that really have been the problem? Can someone explain how?

 

[mcandmar]

I would say either a bad solder joint, or if the center pin of the jack got too hot while soldering it can melt the plastic insulator leaving it loose in the fitting.

 

[denti alligator]

Well, I re-flowed that join at least 5 times, so I doubt it was a bad joint. And just loosening and re-tightening wouldn't explain fixing it if it were damaged form heat.

Oh well, I'm happy it appears to be working.

 

[mkane]

  I had loose nut's. This was the cure until I knew I had loose nut's.

 

[denti alligator]

Well, so far it seems to have been the culprit. Glad to have it resolved. New speaker location is giving me a whole new sound. It's amazing how much difference speaker orientation can make!

 

[denti alligator]

After a day everything sounding fine I woke up this morning and the left channel was barely audible. What's strange is that I didn't touch the jack.

So I fiddled with the jack a bit, and tightened it slightly some more (it was already very very tight). Now it's OK again.

What's weird about all this is that if it is this mechanical problem of a lack of tight connection, why was I getting decent sound and only later poor sound?

At this point I don't expect it to last another 24 hours...

 

[aragorn723]

How about using some glue on the threads to hold the jack tight (or between the screw an nut).  Nothing too crazy, maybe hot glue or some gorilla glue?

Dave