Help on MacII-scanner incompatibility

[bjfeijo@bio.fc.ul.pt]

Dear Networkers:
Maybe somebody has run into the same problem and can help me.
We have a MacIIfx wired to an Apple Scanner through the SCSI bus.
When we had system 6.0 everything was working fine with no detecatble
incompatibilities. However when we upgraded to 7.0 (we're now on 7.1)
the computer started to refuse to boot from the hard drive without the 
scanner "ON", or alternatively, with the cable off-plug. Even if we boot 
from the diskette, the SCSI bus doesn't "see" the hard drive.
Could somebody give me an hint on why is this happening?
Any help will be greatly appreciated! Thanks
Jose

bjfeijo@bio.fc.ul.pt

Jose A. Feijo
Dep.Biol.Vegetal, Fac Ciencias Lisboa, Portugal