Yamaha DTXpress/DTXplorer/DTXtreme

There are photos of it in bits in the photos section.  It is not
difficult to get apart.  From memory, the rubber just peels off and is
relatively straightforward to get back on - it just might take a
couple of goes to get it straight.  If it is not working then you have
nothing to lose.  Could be a bad conenction, although there is some
foam inside which aparantly breaks down over time as well.

Keith.