Behringer BX1200 preamp IC blown

[Bigred69]

My sound went out on the amp so I pulled the head and noticed one of the preamp IC's burnt. When I tried to remove the circuit board I did not realize there was a small blue and white transistor wired to the board that was glued down, and like an idiot I pulled the wires off the board and cant tell where they broke off of. Does anyone have the schematic or a picture of where to re-solder them to?

Thanks Bigred

[Enzo]

I have to admit I don't know what you are refering to. Blue and white doesn't sound like a transistor. And being on wires doesn't either.

So:
Preamp? The board along the front with all the controls? Where is this part glued to? Are ther any numbers on the part?

I don't see offhand anything in the preamp schematic that looks like it would be mounted off the board.

[Bigred69]

Enzo, Thanks for the help. There are two things soldered to the bottom portion of the circuit board. Two wires red and black for the cooling fan and a small blue cylinder with two white wires coming from it which came loose from the solder, but I cant tell where from.

[Enzo]

Well, the fan ought to have a small connector on the end of th wires - little white plastic one. SOmetimes, because Behr loves to glue the connectors together, when you pull on the fan wires, the pc board half of the plastic connector co0mes away stick to the wire half of the connector. The two little male pins which were soldered to the pc board are left behind. SO if you see two little pins sticking up that look like they might fit the holes on the fan plug, there you go for the fan. Shove th connector body back down over the pins. The fan connector is a 2 pin and is connector X1. FInd two pins with X1 printed on the board.

All I can think of is ther are two thermal resistors used as sensors, R3 and R4. I have no idea where they are on th board, but they should be against the heat sink. That is all I can see in the drawing that might be wired. They are in the fan control circuit.