Quadra 840AV with funny SCSI

#1 Sun, 17 Apr 2011 - 09:57

I've got a Q840, and it appears to be quite functional. It has one problem. Its internal SCSI connector doesn't work quite right. Any drives I connect there aren't recognized. Normally this would be a problem, but the external SCSI connector works just fine, and when I removed an internal drive and connected it externally, it booted up just fine.

Question of the day: How do I get the internal connector SCSI to be functional? From what I understand there is only one SCSI buss on this machine (unlike the Q950 which has two independent SCSI busses), so there should be no difference. This used to work, but just one day the internal buss just died. What did I do?

#2 Sun, 17 Apr 2011 - 21:24

I would try a replacement internal scsi cable and double-check the drive's ID and termination in the first instance. Scsi cables can go bad/ there's a reason the phrase "scsi voodoo" entered computer lingo/ a drive with the same number as another (incl. CD) isn't going to get recognized.

#3 Mon, 18 Apr 2011 - 00:20

I had similar issues with my 840AV (some SCSI drives not detected, startup issues) - fixed by replacing the caps with tantalum replacements, all good now.

#4 Tue, 19 Apr 2011 - 04:05

I tried an alternate internal SCSI cable, to no avail. I will look at caps on the board to see if there is any problem. I know it isn't the ID on the drive, since I have taken out the internal drives and they work as external ones.

More diagnosis as it goes.