intermittent white noise

[andywho]

I have 2 of each module except the T15, and they've been working great for over a year now.

I recently began having a problem with one of my J99's: twice now, seemingly randomly, it outputs a steady stream of white noise.

with or without a mic plugged in, the noise is loud with the gain switch at minimum, and increases as the gain is stepped up. at step six (I think), it cuts out and then quickly makes way for a horrid noisy gurgling sound, then at maximum gain, it will sometimes start squealing. BUT this has only happened twice. I'm currently trying to catch it in the act again so I can see if it's passing any signal under the noise.

again, when it's working, it works fine. in fact, it happened just now, so I turned the preamps off and back on, and it started working fine.

I'm about to take the module out for some inspection and repairs, but wanted to know if there's something in particular I should look at when it comes to that.

thanks a lot,
a

[andywho]

well, the white noise has become more frequent. basically, at this point, one of my J99's outputs a steady stream of white noise, with or without a mic plugged in, the level of which is affected by the gain and trim knobs.

I'll be taking it out this week for repairs--any ideas for what might be the culprit, and/or how to test to find the bug? from my searches on the forum, I'll be starting by checking for any funky solder joints.

thanks.