Re: Two 1541-II drives with problems

From: William Levak <wlevak_at_SDF.ORG>
Date: Sun, 20 Apr 2014 04:30:33 +0000 (UTC)
Message-ID: <Pine.NEB.4.64.1404200426070.28398@faeroes.freeshell.org>
Sometimes on these drives, if the head is too far out, when you reset the 
drive, it does not find the directory, and therefore cannot read a file.

There are only two ways to fix this:

    1) issue a block read command to track 1.
    2) open up the drive and physically move the head all the way in.

This is worth doing before attempting electrical repairs.

On Sat, 19 Apr 2014, Ville Laustela wrote:

>
> Hello!
>
> I found out that I own two Commodore 1541-II disk drives, both in a non-working state.
>
> Testing with a measured-good PSU, I got the following results with both drives:
>
> - power on: normal activity (power led on, spindle runs and drive led lights for few seconds, then stop)
> - connected to a C64: drive resets with the computer normally
> - attempting to load halts at "SEARCHING FOR": drive spins (with leds on) but the stepper doesn't move. Only way out is to reset the computer.
>
> By the Ray Carlsen's website (http://personalpages.tds.net/~rcarlsen/cbm/1541/1541-II/1541-II.txt) these symptoms point to either U7 logic chip (7406) or U6 VIA (6522). On one of the two drives I replaced the U7 chip but that had no effect.
>
> Before I start a (lenghty, painful, boring...) removal of the 6522 VIA, I would like to ask here if anyone would have any other ideas?
>
> Cheers,
> Ville
>
>
>       Message was sent through the cbm-hackers mailing list
>
>

wlevak@sdf.lonestar.org
SDF Public Access UNIX System - http://sdf.lonestar.org

       Message was sent through the cbm-hackers mailing list
Received on 2014-04-20 07:00:03

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