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Floppy Disk Not Going In All the Way?

So I changed the 512k Mac's fuse and it is working but the disk will not fully enter the drive and gets stuck. How would I fix this?

 
Good to know it's working at last :)

If yours is an un-upgraded, original 512k (M0001W not D or E), it will have one of those 400k disk drives.

These drives are over 30 years old now and the lubrification they used back then turned into glue 30-odd years later...

My 128k was completely stuck, it wouldn't take disks in at all. But I've seen other cases where the disk couldn't be pulled inside the machine if inserted all the way. My external M0130 drive had this problem. There is a spring that normally pulls the metal tab on the disk and since the disk couldn't get down at all (stuck because of the lube) that spring pushed the disk back.

Is that your problem? Can the disk be inserted in the drive all the way down? It must go down at some point so the head can be in contact with the disk surface. Or does it get stuck halfway down? Anyway, there is only one solution: Re-lube your drive!  ;)

All 400k drives have to be re-lubrificated. I'm afraid you'll have to take the back case off once more and remove the floppy drive from the machine.

Then you need to take the mechanism apart (trust me I've done this and I'm a complete n00b, it's not hard at all)

Get rid of the old grease (alcohol for example)

And re-apply some lube afterwards.

You can follow this guide if you want.

 
The disk seems to basically go as far as the guard then get stuck.

The Mac's display seems to have gone again  :( it now just makes a high-pitched whine.

 
The disk seems to basically go as far as the guard then get stuck.

The Mac's display seems to have gone again  :( it now just makes a high-pitched whine.
You'll have to take the drive apart to see what's wrong.

About the display: your Flyback transformer is dead. You need to replace it.

You should get one of these. Replacing a flyback transformer isn't easy and isn't for the faint of heart. You have to discharge the CRT but if you're okay with that then it's just a matter of de-soldering and re-soldering.

Hopefully, it didn't take the BU406D transistor with it. But if it did you will have to replace that one as well. Problem is they're not easily obtainable nowadays.

 
Ah.... I really have bad luck with electronics...

Still, I think it is only the transformer. Rest of it seems fine. My own fault as I tried to use a 3 Amp fuse instead of 2.5Amp. Either way I'll have to get around to it at some point, thanks :D

 
By the way, how would I fix the mouse port? The connector between the chip (?) and the mouse is gone. Would it be safe to remove a 9pin connector from another port and simply attach it to where the mouse port should be?

 
Could be a few things with the drive. If you want it, I have an 800k drive out of a Mac SE you can use. Free except for shipping cost, of course. It's already packaged and ready to go.

 
What happens if you put an 800K drive in a non-E 512K? Does it just see it as a 400K drive?
It depends on the exact 800k drive. The earliest mechanisms *won't* work in a 128k or 512k because there's a bug in the 64k ROM that causes a divide-by-zero error unless the HD20 init is installed. Later mechanisms have a fix that puts "noise" on the TACH line, which allows them to work. There's a revision letter printed on the mechanism somewhere that lets you tell them apart, can't tell you off the top of my head where it is.

 
The grease on the pins and chassis has completely crystalized.  You're going to need to get some rubbing alcohol and clean it.  Work it until the mechanism moves smoothly, then perhaps apply a little bit of lithium grease to it.

 
How do you remove the floppy drive from its housing/the Mac's housing to clean it? Also is it possible to essentially turn it into a 512Ke?

 
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