Yamaha DTXpress/DTXplorer/DTXtreme

Any hope in fixing this pad?

It's definately NOT the...Cable, module, any settings, modules dip 
switch, etc...and the pads A/B switch doesn't help.

I tested it against an identical TP80S pad which works fine under 
the same conditions so it's 'definately' the pad.

I started to open/peel off the rubber
from the pad to have a look. Some of the rubber wants to come off, 
some of it seems to be glued. Is there anything I can damage by 
opening this, or I should know before opening this pad up? 
Can I obtain/buy any internal components to repair this pad? I know 
I can buy a Piezo at Radio Shack of course...Actually I already did.

I'm hoping that if it's the broken level control, I can somehow 
change the level? replace the level control? Or see if it's a broken 
contact? Maybe it's the Piezo that's bad?

Actually, I forgot to pay attention if the rim's level is low 
too! :/ I DID hook it into (temp replace) my snare pad stereo 
trigger input so I very well could have checked it. But in any event 
the center pad is unuseable at it's very low volume level.

Thanks in advance, Steve