On Mon, 2017-10-23 at 20:14 -0500, Jules Richardson via cctalk wrote:
There appears to be a photo of the internals here, if
that helps at
all:
http://museum.ipsj.or.jp/computer/device/magnetic_disk/images/0011_03
_l.jpg
... it's a little small, so hard to tell what's going on for sure! I
don't?
see any obvious locking mechanism, though.
There's a Fujitsu M2333KS on ebay - item # 182218376023 - which
appears to?
be quite similar in layout. That one appears to have some form of?
positioner / track 0 sensor accessible from outside the HDA if the
logic?
board is removed - is that true of the 2235 too?
Yes, the stepper motor and track 0 sensor is external and, as you say,
you can get at it with the logic board removed (or, to a lesser extent,
though the side of the chassis with the logic board still in situ).
I took the lid off the chamber in the end and confirmed that there was
no latch and the head assembly itself was free to move. It seemed that
the stepper motor itself was the bit that was stuck. So, emboldened
with the knowledge that I probably wasn't about to snap the positioner
arm off, I gave it a rather more enthusiastic shove from outside and it
now does move a bit. I was able to recover the data from the first 26
cylinders but it won't seek beyond track 25 for some reason, possibly
just more mechanical resistance inside the stepper. There doesn't seem
to be anywhere obvious to add lubrication so I suppose I will just have
to try a bit more force and hope that this frees it up!
Phil