[sclug] Problem with CD drives after rebuild

[Alex Butcher]

On Sun, 12 Apr 2009, Neil Haughton wrote:

> 2. I have disconnected each of the drives in turn. At boot the BIOS
> correctly recognises them as master or slave (respectively), and whichever
> one is connected will automount a CD (and /dev/hdc, which is the DVD drive,
> will also automount a DVD). It seems therefore that the problem arises when
> they are both connected. Perhaps my only recourse now is to replace the
> cable when I can scrounge one to try out. If that solves the problem I know
> what I have to do. If not.....

1. Always check the physical layer first.

2. It's usually the cable. (as a friend from BBLUG puts it).

I try to keep spare cables on hand for such eventualities. If the cable's
duff, all sorts of odd behaviour becomes possible.

As for the cabling itself, check you've used the cable the right way, and
that it's no longer than 18" (maybe as little as 9" if you're using both
channels and have a crappy PATA controller, like the CMD640 was).

PATA devices should be cabled as follows


#======================#=========#
|                      |         |
Motherboard            Slave     Master

Note that the longest segment of the cable should be between the motherboard
and the Slave device. If no Slave is present, only the two end connectors
should be used. Many systems will no doubt be tolerant of incorrect cabling,
but the above description is as per the ATA spec.

> Regards,
> Neil.

Best Regards,
Alex.