So, I just got a used Edirol PCR-50 for $75 - do you think that's a good deal? The key just below the "check sum" heading, an "A" key, seems to be out. This strikes me as a deal breaker. I have the opportunity to bring it back tomorrow if I want for a refund (provided I don't break it). Basically, when I hit the key, it makes noise, but it's quieter than the others. Makes a big difference on the Piano instruments, but not so much on other stuff. Any suggestions? Is it a software setting? I'm running this through GarageBand, and will con't. to do so if I keep it. How much to replace the sensor for that key? Thanks ahead of time. I'm excited to begin my foray into midi-music. R.