On 10 Apr 99, at 13:36, Changhsu P. Liu wrote:

> Usually, I disconnect and connect external SCSI devices when the
> computer is on and nothing have happened so far. I guess it's more
> risky to do this on an internal device.

  It took me a bit of extra attention to realize that this was with an
internal device.  Unplugging and plugging-in external devices *may*
sometimes be an acceptible risk (although never recommended) -- this is
basically *never* the case with internal components.
  Think of the power supply as a shield between the delicate internal
circuits and the outside world.  An external device has its own power
supply, and so you can make/break an external connection without
affecting power to any part of the equipment.  But changing any inboard
connector, especially one that may be carrying power, can introduce
spikes and other mishaps on the internal "power grid" that the power
supply cannot reliably defend against.

  You appear to have gotten off very lucky this time.


David G

            PCBUILD maintains many useful files for download
              on our web site - visit our download page at:
                     http://nospin.com/pc/files.html