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400k drive microswitches

Corey986

Active member
Ok.  My new to me external 400k drive doesn’t see when a disk is inserted.  I cleaned and lubed the ejection mechanism already.  The drive was pretty dirty, so I’m guessing the microswitche(s) are dirty.  Before I take the whole drive apart, are these optical because they look like a U shape with a piece of plastic going down the middle attached to levers and stuff or are they simple mechanical switches?  That will help me figure out how to clean them.  If mechanical, would flushing them with ISP in an eye dropper help, then actuating them a whole bunch of time.    Also any hints for cleaning the switches would be helpful. 

Thanks,

Corey

 

Dog Cow

Well-known member
Yes, they are optical switches. In dim light, you can see the "red eye" glowing from inside the drive.

 

Corey986

Active member
OK, thanks.  Well I cleaned them with 99.9% ISP and still nothing.  When I insert a disk, the drive spins, but the computer doesn't see that a disk is inserted.

Any ideas on what to check?

Thanks,

Corey

 

bibilit

Well-known member
Hi,

Are using a 400k disk (or 800k) ?

Also, is the disk going fully down ? and the pressure pad present ?

 

Corey986

Active member
I'm using a scratch disk that should prompt me to initialize, the system doesn't recognize anything is in the drive.   The pressure pad is present and it does go in all the way.

Thanks,

Cheers,

Corey

 

Dog Cow

Well-known member
With nothing in the drive, you should be able to press down on the small black upright pin that's at the front, and right side of the drive.* The disk motor should spin, and after a few moments, you should get a dialog on the Finder saying the disk is unreadable. Are you getting any of that?

* It's shown in this photo, part of the square black component marked 491

 
Last edited by a moderator:

Corey986

Active member
Thanks, solved it.  It seems that there was a cold solder joint on that front microswitch.   It wasn't glowing.  now it is...

All seems good now...

 
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