Sunn SX8350 Powered Mixer

[flon_klar]

Hi guys, hope someone can help me. I've got an old Sunn SX8350 powered mixer that's been working fine for the past couple years that I've had it. Suddenly, it started having an issue: I can be playing through it just fine, and out of nowhere the volume will either fade out or the sound will just quit. Sometimes it comes back on when I turn the switch off-then-on, sometimes not. If I happen to be playing a guitar through it, I can unplug the guitar, and when the speakers "pop" it brings the volume back up. Anybody smarter than me have any thoughts about this? I'd appreciate any input. Thanks.

[Enzo]

Check the cutout contacts on the patch jacks. On the front, the various jacks like power amp in and graphic in and so on.

[flon_klar]

Enzo-

Thanks for the advice. When the amp cut out the next time, I plugged a cord into the "Main Out" jack- nothing. Then I plugged into the "Monitor Out" jack- BAM! the amp came on, and it never went out again during the next 30 minutes that I played through it. So what is it, just crap built up on the terminals that needs to be knocked off every once in a while? Thanks for your help.

[Gtr_tech]

The jack contacts oxidize, get dirty, crack loose from the board, etc. Clean them first then check solder if its still intermittant.