Re: Two 1541-II drives with problems

There's an easier way:
    3) Initiate the disk.

But, that condition jiggles the head (moves the stepper motor), and doesn't 
jam the computer; so, it isn't his problem.

-----Original Message----- 
From: William Levak
Sent: Sunday, April 20, 2014; 12:30 AM -0400

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:
>
> 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 a few seconds, then stops)
> - 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), 
> those 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 (lengthy, painful, boring...) removal of the 6522 VIA, I 
> would like to ask here if anyone would have any other ideas?
>
> Cheers, Ville


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