Re: 1541 bad R/W head

From: silverdr_at_wfmh.org.pl
Date: Sun, 25 Feb 2018 21:19:56 +0100
Message-Id: <DAE9C27F-BBC9-42CC-9C6A-A29857B915D0@wfmh.org.pl>
> On 2018-02-25, at 20:31, Francesco Messineo <francesco.messineo@gmail.com> wrote:
> 
>> You may try to replace the head. Is this the "turn" or "push" type of mech? I think I have somewhere an incomplete "push" mech, which should have a working head.
> 
> it's the turn one. The newtronics D500, is the most widely used in the
> 1541-II, but was used in many 1541s.
> I think replacing the head would require a re-alignment of the stepper
> too, which is something I can do, but I would rather avoid unless this
> happens to be the last disk drive on earth :)

It's not /that/ hard. I did it a few times on 5.25 and a lot of times on 3.5" where people notoriously used to tear the heads out or otherwise, mechanically damage it.

>> Happens. Rarely but happens. To other types of tightly wound coils too.
> 
> it's my first encounter with this failure, that's why I wondered.

I ran a workshop back in the times and had much bigger sample, I guess. Literally hundreds (if not four figure numbers) of those passed through it. I remember this type of failure twice, I reckon. So yes - it is a very rare failure. A fraction of a percent.

> Who
> messed with this drive before me, managed to install a 74LS00 in place
> of one of the 7406. It rended completely inoperative both the activity
> led and the head stepper, but fortunately didn't  ruin the custom
> logic array.
> I wondered if maybe the same person could have killed the head too...

Could be. Who knows what (s)he was thinking and connecting (where to).

-- 
SD! - http://e4aws.silverdr.com/


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Received on 2018-02-25 22:00:02

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