Punch125.2 burnt diode near treble control

[spooney]

I have a Punch 125.2 that is in need of a new gain control.While removing the original one today i noticed that right behind the treble control there is a diode that looks burnt as well as the smd components directly next to it. When I originally tested the amp the treble control worked fine so i'm kind of curious if the diode is even part of that circuit or if the parts although charred may have survived. Here is a pic of the damaged area. Its hard to tell that the diode is burnt in the pic but i just wanted to show the general area of the problem. Any info would be greatly appreciated.

[Perry Babin]

If one end connects to the shield ground and the other end connects to chassis ground, it's a 1n4003. The resistor in parallel with it is likely a 1k. If there's an SMD cap, it's likely a 0.01uf. You can email rockford for the schematic to confirm this.

If you ever have a punch amp that has engine noise and you can't figure out why, measure the resistance between the shield and chassis grounds (no signal cables plugged in). If it's near 0 ohms, look for a shorted diode like this.