ST506/412 failure modes? (in this case, an IBM 0665)
jules.richardson99 at gmail.com
Mon Oct 12 13:53:56 CDT 2015
This may be forgotten knowledge - or perhaps more likely, something that
was never known in the first place - but are there any typical failure
modes of ST506/412-type drives (beyond the obvious mechanical damage
between heads and platters)?
I've seen quite a few dead drives over the years, but of course haven't
invested much time into thinking about what might actually be wrong with
them, because they were once quite common. Now that working ones are
getting scarce, it got me wondering if there were any obvious things to check.
In this particular instance, I've got an IBM 0665 30MB drive in a Compaq
which spins up, bounces the heads around a little, then causes the machine
to issue a fixed disk failure at boot time. This is an embedded servo drive
with a voice coil, not a stepper type. Oddly enough, it passes Compaq
diag's spare cylinder read/write tests, but fails the seek test. I've not
tried a LLF yet because I was interested in trying to salvage whatever data
might be on it first; there are several large ASICs in the logic board, but
also a lot of more common stuff, so it's possible that the fault is
something fixable - but checking component by component is probably more
trouble than it's worth.
Yeah yeah, MFM emulators and whatnot... but I do want to keep noisy old
boat anchors alive in my machines for as long as I can - while a modern
replacement is the only long-term solution, I always think of modern tech
as detracting from the experience of using old hardware.
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