i bought a sp808 from a friend, it seems it has the OP board with SCSI..but when i connect a external zip drive, the unit powers off, and doesnt come back on until i disconnect the SCSI wire.. can someone point out if im doing something wrong, or if i missed any additional steps?

Are you sure the Zip drive is SCSI and not parallel? Old 25pin SCSI is very similar. Also- Zip discs fail randomly and should NEVER be trusted as a reliable storage medium- I would strongly suggest another Zip drive be used on a computer to copy important materials to a computer or other backup drive.
Om

thank u!