Is that an EMX88s? I don't know if they made a different one with no "s" in it. I have an EMX88s and found the switch to from stereo to mono/monitor and bridged mode can be kind of flakey, so watch for that. Where are you injecting signal? Do you have mixer/preamp functionality?
When you say "no reason to fix it" is that because there isn't a customer paying to have it fixed? I actually think it is a pretty nice unit, and worth fixing, but then again I have been known to spend hours working on $50 amps because I don't want to throw them away.