Sequential circuits samplers

Hey. I as curious to know if anyone else has had a similar problem
with their prophet 2000.
The fuse has recently blown when I went to power on the unit.
I had an effects box plugged into the mono-out jack that was turned on
but I'm not sure if that did it.
I changed the fuse to the proper specs (1/2 amps in USA,also they were
slow blow),and when I turned it on it just blew again.Three fuses
later I figured something else is up.
Anybody got any ideas about this blasted thing??
Similiar situation??

Thanks in advance.