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800 k floppy drive troubleshooting
Posted by: bibilit on 2016-04-14 06:04:15
i have had some issues with 800 k drives recently, and wanted to know if somebody has figured out how to troubleshout those.

Apart from the usual cleaning, lubricating process, i came across the following issues:

Floppy carrier stuck in upper or mid position: found the eject motor wasn't working properly not allowing the carrier to go down to the bottom position.

Eject motor working all the time, so trying to eject a floppy which is not present : found to be related with the drive circuit board (swapping board solved the problem)

The last issue i am trying to solve is related with a drive unable to boot from a 800 k disk, but able to boot from a 400 k one.

I think this is related with the upper head not working properly (i have the happy mac, then the disk is ejected) but i wanted to know if i am in the right direction.

Posted by: bibilit on 2016-04-16 00:58:34
this is related with the upper head not working properly (i have the happy mac, then the disk is ejected) but i wanted to know if i am in the right direction.
Replying to my own post.

So i have a half working drive on one side (the drive will be able to boot properly the machine, but the eject motor is spinning all the time) and another drive the other way round (motor ejecting and working properly, but unable to boot)

Swapping components didn't worked (the good head was removed and swapped in the good ejecting motor drive) and was unable to boot properly.

So both problems are related in the circuit board side...

Posted by: CC_333 on 2016-04-17 00:18:43
On the one that ejects constantly, are you using the proper cable? If you're using it with a Plus*, you need to have the yellow-striped cable to prevent the very thing you're experiencing (constantly running ejection motor). On the other hand, it could also be a faulty sensor switch (a cam separates a pair of contacts to signal the motor to stop).

c

*You shouldn't need this cable on other models, like the SE or II/x/fx, but I'm not 100% certain of this.

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