Yamaha DTXpress/DTXplorer/DTXtreme

I just got a used DTXP I for Christmas, so I'm trying to learn how to
use it.  Can anyone point me to a help source other than the manual
that came with it?  It's badly written and doesn't really explain how
to get to this menu or that menu.

I built my own triggers and can't get a peep out of the unit when I
hook them up, so I don't know if my triggers are bad, the unit's bad,
or I'm doing something wrong in the configuration.

Thanks very much.  From just skimming the posts, this looks like a
knowledgeable, helpful group.  I'm so glad I found it.