disk medium error

i was looking for help on this question and found my own post from a year ago. i still havn't found any help. someone?
my sp808ex will not sample. when i try to format a disk it quits out of the formatting before it is finished. when i turn off and then back on, it tries to read the disk a few times then says "disk medium error". i've tried four different brand new 250 mb disks. do i have to replace the drive? and can i replace it with any ol' internal 250 mb zip drive?

thankis