Apple IIc internal drive stepper motor issue

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Apple IIc internal drive stepper motor issue

I've been trying to troubleshoot an issue with a IIc internal drive, but hitting a wall in my skills - I hope someone here can provide some insight.

On boot, the drive will spin up, the head will move back to track 0, but it will not read. This issue is not related to the analog board or the speed control board, as I've been able to swap in known-good boards and the symptom is the same.

So I'm supposing that there is an issue with one of the connectors or cables to the stepper motor, or perhaps something to do with the r/w head.

Has anyone had any experience with this, or have any suggestions of what to be looking for next?

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Sounds like the stepper motor

Sounds like the stepper motor is working fine.

 

More likely to be either a dirty head or track alignment. Or broken connection to the head.

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Have you cleaned the read

Have you cleaned the read/write head?

After cleaning, does it still not read any diskette?

 

If the stepper motor is moving the sled back to track zero on bootup then it's very likely working properly.

 

 

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Good grief

So, yeah, it was a dirty head. Such a rookie oversight. I couldn't see the blemish when looking at the head straight on, I had to get the light / reflection *just* right to see it, exactly in line with the mag strip... Took a bit of a scrub, but everything's right as rain now.

So even though it *looked* clean, it pays to really check.

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desertrout wrote:So, yeah, it
desertrout wrote:

So, yeah, it was a dirty head. Such a rookie oversight. I couldn't see the blemish when looking at the head straight on, I had to get the light / reflection *just* right to see it, exactly in line with the mag strip... Took a bit of a scrub, but everything's right as rain now.

So even though it *looked* clean, it pays to really check.

Check your diskettes, too.

The biggest cause of read failures (and diskette destruction) is mould.   Mould grows on the surface of the media and it accumulates on the read-write head.

That buildup causes the read-write head to begin to scrape the surface of the diskette and physically scrape off the magnetic media thereby destroying the diskette permanently.  I'll wager that more than one of your diskettes has a concentric scratch at track zero.  

 

Mould can be hard to spot, but it appears as a blotchy, satin, or mottled surface on the diskette media.

It's difficult to remove and once it starts the only fix is to image the disk with ADTPro (or AppleSauce) and discard the original.

 

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Thanks

This is good info for folks to keep in mind. Thanks. :)

In my case, I'm okay on that front. Any of the disks I used in this machine were recently made (Athana) - I actually only own a handful of original disks, and none of them were used in this drive (and I only use copies of them anyway). This machine only came to me a few weeks ago with RAM issues and a non-functioning drive, and I've only ever used recently-made diagnostics disks in it - and they continue to work fine in other drives.

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