22 Apr
2010
22 Apr
'10
1:44 p.m.
A quick update: The drive spins up, comes ready and
is passing the seek
test in Morrow's FORMATHD.COM utility. The header read fails on all
Sinc this drive has a transparent cover, I assume you can see the heads
moving during the seek trst.
sectors and all cylinders, so something is still
amiss. I tried
re-writing the sector headers (if I interpret correctly, it is possible to
simply rewrite the headers without disturbing data in the sector proper -
That is not unheard-of. Howeever, I would be a little wary of writing to
a drive that didn;t read correctly. If something is faulty, it's quite
possible it's going to write somewhere it shouldn't. And since the drive
fails on every sector, I would think the fualt is unlikely to be simply
bad formatting data on the disk.
a new one on me!) but that didn't help. No error
on write, but they
cannot be read back.
What error do you get if you try to read them? Does it manage to find
anything?
I'll start poking around in the read logic next. Getting closer, anyway.
I've not looked at the schematics, but I guess I'd start by seeing if (a)
it was reading anything (do you get any sensible-looking pulses at the
read data output -- and rmemeber that in 99% of drives the pusle width is
irrelevant, it's set by a monostable on the logic board, it's the pulse
spacing that defines the data), and (b) is it selecting one (and only
one) head
-tony