If you want a gentler solution, spin the drive on its axis before
booting up. I had a Zenith portable that had stiction and that solution
worked every time.
Sam Goldwasser wrote:
Ken Weitzel writes:
Sam Goldwasser wrote:
"William R. Walsh" m writes:
Hi!
Before you buy, why do you think the controller has gone bad? In a
system old enough to use MFM drives there could be a lot of reasons for
a problem. What's the system doing or not doing? Any POST error codes?
Good points, all of them. Checking to be sure that the system's CMOS battery
is still running would be an excellent idea. After years of sitting it could
be dead or depleted. (Many older motherboards used a rechargeable NiCad
"accordion pack" battery.) If yours has a battery like this, leaving the
system powered on overnight might bring it back up. They do seem to be
pretty robust.
You may want to clean the contacts on the drives too - considering they
use card edge connectors.
Be ***very*** careful if you do this! If you can help it, do *not* remove
those hard drives from the system unit. ST-251 drives have stepper motor
head actuators that are subject to falling out of calibration with the
information stored on the drive platters if the operating temperature range
changes or the drive is removed and reinstalled. There are only two ways out
of this if you get the drives working--either hope that you can find the
right climate/installation "sweet spot" or low-level formatting. Low level
formatting will destroy all data on the drives.
Can you cite a reference? In my experience, MFM drives are about the
most robust things on the Planet. 
The tracks are so far apart that
normal temperature changes have no effect. I have some ST-251s (I think
that is the model) sitting at the bottom of a closet. I bet if I could
find a system today to power them up, they would work just as well as
20 years ago (if the grease hasn't congealed).
Hi...
Anyone else remember "stiction" ?
Yep, been there done that. A good whack on one corner was one method!
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"The RFI-EMI-GUY"©
"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."
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