There must be another one
Not necessarily. The main 5A fuse probably covers the whole power supply, and
the audio amp is probably powered by a DC tap off of that. So it wouldn't need
it's own fuse (as it probably doesn't have it's own PS). If there was a fuse,
other than the ones accessible
Did you ask these guys?
_http://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=forum;f=5_
(http://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=forum;f=5)
If they don't know then nobody will. They'll have the answer.