Behringer KX1200 w/ output problem

[pontiacpete]

Left it on for about 1/2 hr and found a burnt trace on the pre amp board. This trace lies between the holder legs of 2 pots. It's a ground trace.
All ICs on all boards does seem hot to touch.
I fixed the trace and still no sound and no hot ICs.
The lettering/numbers have faded alot on IC8 , 9 and 5 making them hard to read. IC5 is the hardest to read even under the highest magnification that i can make here. No cracks can be detected so far.

Here's a picture -

[Enzo]

If yo0u have a burnt open ground trace on a preamp board, it is almost certain something was plugged into an input with either a hot chassis or some other reason that trace had to carry a lot of current. And such a trauma could well have destroyed all the ICs on that board.

ICs 6,7,8,10 are all TL074.
IC9 is 4580
IC6 is TL062

ICs 1-4 are Vregs and power amps.

Is the power amp assembly on that unit a sort of cube-ish shaped thing in the middle? Should be a ribbon over to the preamp board. Disconnect the preamp board. DO your 15v rails both come up then?

[pontiacpete]

That's weird. Wonder how they managed that?

Anyway, yes, this is the one with the cube in the middle of the chassis.
Unplugged the pre and fired it up and it's making the + - 15v.
Guess I'll go ahead and change out the pre amp ICs . Did the one on the back board already, now I have to order some 4580s

[pontiacpete]

Finally replaced all the ICs on the pre amp board, and the amp is working.
Many Thanks to everyone for the help!
pete