Re: SCSI Bus hanging

Juergen Sauer (
11 Apr 1997 12:20:27 GMT

Detlev Offenbach <> schrieb
am 4 Apr 1997 17:56:10 GMT in
DO> Hello Gurus,

DO> I have a brand new 200MHz Pentium Box with an Adaptec 2940AU Controller.
DO> Everything works fine except that the sound module cannot find the AWE32
DO> extension of my Soundblaster 32 board. The SCSI controller is working
DO> without any problem. However, after I used the CD-ROM, which is a Pioneer
DO> DRU-12x, the SCSI bus is blocked at the next reboot. Reset does not help. I
DO> have to power off my box. Any idea what is causing this problem?

There are this posibilities:
- your CDROM is not Ultra SCSI, slow down the whole SCSI BUS to
max. 10 MHz SCSI clock

- outdated drivers (The 2940 family is a big bunch of chipsets,
Adaptec changes the chipsets really often, like othe people
their clothings)

- ugly bad cabeling, the 2940AU is an Ultra device,
most standard cables may not work properly

- ugly bad external cables, some dealer sells poor quality cables
(not paired, single shielded) cables as Ultra cables!
a real SCSI-II should be about 10-15 mm diameter

- improper termination. You really need active (Term Powerd)
terminators, probably you should use external termination,
disabel the automatic termiation of the 2940, terminate internal
bus with a special active terminator plug on your last plug.

- don't use external Scanners of the brand Mustek - those lamers
does not know anything about SCSI and termination.

good luck

Jürgen Sauer Tel. +49 4209-3021
Neue Str. 11 +49 172-4254411
28790 Schwanewede/Germany FAX +49 4209 5217 CI$: 100013,1564