>Is the rest position of the stepper arm at the furthest extreme from
>the track 0 sensor? From memory, that's where it should be after a
>short idle period (e.g. end of self-test).
Yes, that where it sits.
>Maybe a seek to a specific track is taking a different code
>path and reading corrupt data from the on-board RAM that says "you are
>on track 0" when it's not? Again, just a WAG.
Yes. I did wonder if it might be a RAM issue. I could go searching for some equivalent RAM chips to swap in I guess.
I can see this problem is not going to be an easy fix. It might have to wait until winter, when I can get the scope out during those long nights and delve into the problem. It's summer here right now and not that conducive to long periods squested in the computer shack (not according to the rest of the family anyway) (-:
Terry (Tez)
On Jan 22, 1:38 pm, Terry Stewart <te..._at_email.domain.hidden> wrote:
> Would it be a break issue if the ProFile self-checks? It seems to do this
> successfully at almost every switch on. The stepper lever moves right
> around quickly (to track zero?) then moves smoothy step by step back to
> it's resting position. Similarly is this likely to occur if the HAL
> device(s) weren't reading the tracks properly? Speaking of these, are the
> HAL devices easy to identify? No one knows of an image I could use for
> reference do they?
If it's reliably coming ready (which it would have to be in order for the self-test to start), then don't worry too much about it. FYI: On the bottom of the sealed HDA is a flywheel with a little metal arm sticking out of it. Immediately adjacent is a chrome cylinder about 1/4" in diameter and may 3/4" long with two wires coming out of it. It sits in a groove and is clamped with a small bracket and single screw. Very obvious once you get the electronics board off the bottom on the drive. But, "..if it ain't broke, don't fix it" - and it sounds like that's not an issue for you.
> The ProFile sounds like it's trying to access the drive. Lights blink and
> the stepper lever sits at it's resting position and vibrates (buzzes)
> about
> three times...then just gives up with an error 83.
It's puzzling that the stepper is working during the self test and not when addressed for data I/O by the computer. I don't know the circuit well enough to give you an idea where to start looking, but in broad strokes the computer says "Read sector X" and the microcontroller in the drive figures out the offset of that sector, calculates the number of pulses to reach it and commands the stepper motor accordingly.
Is the rest position of the stepper arm at the furthest extreme from the track 0 sensor? From memory, that's where it should be after a short idle period (e.g. end of self-test).
Just thinking out loud: If the firmware was confused as to the current track, maybe it's trying to move in the wrong direction and slamming into the mechanical limit? Seek track 0 is a brute force operation that simply pulses the stepper toward the outside of the platter until the opto-sensor sees it, so that may not use the same logic. Maybe a seek to a specific track is taking a different code path and reading corrupt data from the on-board RAM that says "you are on track 0" when it's not? Again, just a WAG.
-- ----- You received this message because you are a member of the LisaList group. The group FAQ is at http://lowendmac.com/lists/lisa.html To post to this group, send email to lisalist_at_email.domain.hidden To leave this group, send email to lisalist+unsubscribe_at_email.domain.hidden For more options, visit this group at http://groups.google.com/group/lisalist -- ----- You received this message because you are a member of the LisaList group. The group FAQ is at http://lowendmac.com/lists/lisa.html To post to this group, send email to lisalist_at_email.domain.hidden To leave this group, send email to lisalist+unsubscribe_at_email.domain.hidden For more options, visit this group at http://groups.google.com/group/lisalistReceived on 2012-01-23 07:39:00
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