DG MV/2500 Help

Well I got the PSU repaired in the MV/2500 I'm trying to resurrect; now I'm on to disk problems. On start-up I get Model # 8932; System Processing Unit (SPU) AB, FAILED; ERROR 6:252:74 I know that Break (CMD-ESC) will take me into some sort of primitive boot environment but I have no documentation (or knowledge) of available commands etc. Next steps: * Try to get the MV/2500 system media on 130MB CTD format * Try to get low-level documentation on the MV/2500 * Find out how to attach a PHU to the MV/2500 (no, it's not obvious!) * Find out for certain if I can put non-DG SCSI disks in the MV/2500. The two disks in there appear to have DG-originated BIOSes... Can anyone help or answer any of the above? Thanks in advance, Steve -- /Stephen Merrony /http://stephen.homedns.org/dg/mymv2500.html