Distek Disintegration 3100 arms stuck in raised position

Hello.  I have a Distek Disintegration 3100 apparatus with the arms stuck in the raised position as like it would come when shipped.  The unit powers on, the LCD display works, and various function buttons seem to be working correctly except for the raise and lower which do not respond when pressed.  Has anyone ever experienced this, know ifthere some type of locking mechanism, or  know where the fuse(s) are located?  Thanks!