mixer trouble - help!

[ugo]

my mixer, a behringer MX2004A, just started freaking out on me and i'd like some advice on if it sounds like it can be repaired cheeply enough or if im going to have to buy a new mixer.

here's whats happening:

when i switch it on i get a loud buzz...like a grounding problem. its mainly on the left channel but i hear a slight bit of it on the right. after several minutes, the buzz starts to fade until it sounds as if its pretty much cleared up. then it will occasionally pop and crackle. eventually, anywhere from a few minutes later to a few hours, i'll get a final pop and all the sound will cut out, the PFL light comes on, and the rest of the lights go out.

if i shut off the mixer, then turn it on again. the whole cycle starts all over again.

so...anyone here seen this before? how bad is it?

-ugo

[ew]

My first guess would be a bad solder joint in the output stage.When it's cool,it has limited contact-hence the buzz.As it warms up,the wires expand a bit;hence the clearing up.At a point,the joint gets really warm and separates(like a thermostat);hence the shut down.
The other thing it could be is a loose or cracked PC board flexing-same rationale behind what it does.
ew

[ugo]

thanks for the reply. i'll check around in there and see if i can find a loose connection. i wish i knew more about electronics though. (i usually only work on simple stuff like electric guitars.)

is there a particularly good way to find loose joints on chips/boards?

-ugo