Hi,

Just got a used 303 and so far I've been unable to play anything through the 303 to either record or apply effects using the ext source pad.

I've checked by main volume and input levels, everything seems fine. After reading through the manual again I can't think of anything else except that the input is not working.

Any ideas?

i hope is not an RCA problem...

possibly the plugs at the back have become loose and arent connecting to the circuit board properly..
wiggling the plugs might tell you if a bit of sound gets through.. but they might be completely disconnected..

if you know how to use a soldering iron or know someone else who does its a very simple thing to check for/fix

My guess is rca's as there also seems to be a problem with one of the channels. I'd open it up ( i have a soldering iron) but I'll probably just return it. Ah, the promise and the perils of the internet.....