Get a sheet of glass.
In a not too dusty area (hint A/C has filers usually)
gloves on
Top off glass on - all will be revealed.
Rod - Digital Equipment Corporation 1975 - 1985
On 27/02/2024 03:50, Chris Zach via cctalk wrote:
Oh wait, that sound? Over and over?
I had a RD54 type drive that I hit with a magnet by mistake and took
out the servo platter. Got that sound, over and over because the drive
used servo loop positioning and couldn't find the servo track.
Since you probably didn't do this, check to see if you get a signal
off the servo head, and the preamps there. That might actually be it.
C
On 2/26/2024 5:28 PM, Jacob Ritorto via cctalk wrote:
Thanks for the good ideas and convo everyone.
Now please do note that I can definitely hear motor/platter spinup
happening so it's definitely not "heads stuck to platter" stiction.
I hear the lock unlatch and I *think* I even hear the heads load and fly
(comparing what I hear on this drive to other drives I've actually
seen the
guts of in flying action) so I substantially doubt it's "arm stuck to
lock
pad goo" stiction.
So we've made it through a lot of the powerup sequence and the
problem is
at the final part - the track scan up and back down the surface - the
phase
when the signature "...blearrnnnnt-meeeeeelrp..." happens :)
And yes I believe from memory that XT-2190 is supposed to make the same
track scan noise as the XT-1140 (I have an XT-1140 running perfectly
as a
fake RD54 in another pdp here).
So could my behaviour of being hung at the final phase - the track scan
noise - be the result of a lost servo track? Thinking about that,
didn't
someone on this list kill an XT-2190 recently by taking an outrageous
magnet to it? Did you get the same track scan failure as I'm getting?
Confused electronics on the PCB?
Something else?
Where would one begin diagnosing this particular problem?
I did try the wrist twist torquing thing.
And lightly whacking side of housing with palm of hand during track scan
noise. Declining to do that hard, tho.
Powered off and back on (to retry) probably near a hundred times now.
Heated it gently in front of our forced-air furnace duct until
comfortably
warm to touch - probably near 105 F.
All these produced absolutely zero behaviour change.
thx
jake
