This is a link to site which lists all the reset sequences for a huge number of pieces of gear.
If you have ever had a device just go crazy, this chart will tell you what to do to reset the device to the factory set-up. Yes, you will loose anything you didn't back-up, but it will reset the device with out a costly trip the service depot! also needed after replacing the battery on some units.
I know all you PLanetZer's dont' use external devices...right?
http://www.rangeraudio.com/presets.htm
R