Troubleshooting an EQ?

Hi,

Sorry, I know this is a bit outside the scope of this forum, but I figured someone here may be able to give me a few pointers.

I recently picked up a battered Klark Teknik DN410 parametric EQ. Looks like this:

http://www.musik-produktiv.co.uk/bilder2/00/28/05/002805008xl.jpg


One channel has a weak sound, and seems a bit intermittent. I'm guessing it's a loose connection, dirty/worn pot or switch, or a broken track. I'd really like to troubleshoot & fix this myself.

So, can anyone tell me (or point me to) a sensible process for isolating the fault.

Thanks

Perhaps the easiest first step would be to poke around inside with a chopstick to see if touching or wiggling anything has any effect.

If that doesn't find the problem, I'd use a signal generator and a scope. It would be easiest with a schematic, but having a working channel for comparison is almost as good. The idea is to apply an input, and probe at various points, moving from input to output, to see where the signal stops.

Thanks for the guidance, that seems quite straightforward. I will have a look this evening.