These are the instructions for resetting an MX-8 from an old forum post:

1. hold function+reset and power on.
2. "test mode y/n?" press yes.
3. rom version -- press function
4. "route test" press function
5. it says "fail" that's okay. press function.
6. "destructive test y/n" press yes.
7. "ram test/ram good" press function.

you should see an elapsed timer. turn the power off. wait a few seconds. turn it back on. it should be at "#1 INIT".

if this doesn't rectify the problem, you can send it in for repair. we charge $65 + parts + shipping for non-warranty repairs. please call first to get an RA# (return authorization) and shipping instructions.

thanks!

Josh Fiden
President
Digital Music Corp.
http://www.voodoolab.com