Heres some sites that list factory resets for loads of drum machines and synths etc etc
http://spmm.fr.free.fr/tests.htm
http://www.dlse.nl/synthrepair/reset.html
The first one is in french but its pretty easy to figure out.
Thanks to S-CAT for the second one.
If you have any more useful links along these lines postthem on this thread
Could be useful. Has a lot more brands then the one at http://www.yamaha.forums.co.uk (http://www.yamaha.forums.co.uk)
Whoops, I meant to say yamahaforums.co.uk