Apple Scanner: Unable To Be Recognized

I have had difficulties with a Macintosh SE/30 and my Apple Scanner.

When the Macintosh SE/30 is connected to the Apple Scanner, it doesn't recognize the scanner. The scanner does, however, work with a Macintosh IIx using the same cables and terminator.

I was finally able to make the connection between the Macintosh SE/30 and the scanner by putting a new hard drive in the SE/30, but I still don't know what is happening. Can you help?
You have an issue with impedance matching.

This is a known situation with the Apple Scanner. It occurs when the impedance created by a combination of devices and terminators on the SCSI chain causes one device to be "lost" on the chain.

There is no official service procedure. A workaround is to change the impedance of the SCSI chain by adding one or more terminators, SCSI devices, or an additional SCSI extender cable. The device in question should reappear.
Published Date: Feb 18, 2012