alexis@ccnysci.UUCP (Alexis Rosen) (05/31/89)
In article <4002@uhccux.uhcc.hawaii.edu> mikem@uhccux.uhcc.hawaii.edu (Mike Morton) writes: >I've had intermittent problems with an 80Mb internal drive in an SE/30. >It sporadically won't boot. When it's refusing to boot, running HD SC Setup >off a floppy tells me there are no "suitable" SCSI devices attached. This problem seems to be cropping up more and more frequently these days (I've seen it three times in the last month) so I think it's time to tell the whole story. Many drives, not just the Quantums, can suffer from a problem known as "Stiction." This is when the head and the media stick together (because they are so smooth). This is just enough to prevent the drive from spinning up when it first gets turned on. The cure for this is quite simple: Simply rap the drive on the side when you turn it on. Don't be afraid to hit it (after all, if it won't boot, you've got very little to lose). This will jar the heads loose from the platter, and the motor will be able to start it up. Note that if you hear it spinning up when you turn it on, stiction is NOT your problem and hitting the drive won't help at all. Interestingly enough, this problem was at the root of LaPine's developement effort. They built a lifter machanism to move the heads away fromthe disk at spindown, but they never did get it working quite properly. Now LaPine is just a memory, so stiction may yet be with us for a while... >Question: If you seem to have trouble only when booting, should you leave >your flaky drive on non-stop while waiting for a replacement? Or will this >cause the problem to get worse? If stiction is your problem, this is definitely the answer. It won't have any effect on the drive at all. Of course, you should get a new drive as soon as you can. --- Alexis Rosen temporarily at spector@vx2.gba.nyu.edu alexis@rascal.ics.utexas.edu (last resort)