Emax

So I just purchased an Emax SE HD rack.

Problem - 
When amplified an enormous amount I can hear what sounds like samples playing and the pitch tracks with the midi notes, but it is barely audible.

The volume slider has no effect on the barely audible noises I'm hearing.  (calibrated volume slider with no results)

I've plugged an external synth into the sample input and can also barely hear it when the emax is amplified a lot.  Interestingly, I can still hear this even when the emax is not turned on.

So are there any tests I can do to diagnose the exact problem?

When plugging into the sample input, should I be able to hear whatever is being fed into it easily?  I'm very unfamiliar with how one should work.

Is it possible one of the foot pedal inputs is affecting the volume at all times even for the sample input?  (I had an issue like this with my memorymoog)

These functions seem to be working...
- loads up from floppy disk and loads presets (hard drive doesn't work)
- ran midi diagnostics and it is receiving midi correctly
- all buttons on front panel are working properly

Thanks in advance for any help!  I really really appreciate it!

-RJ