SuperDrive (floppy) maintenance

[JDW]

There is yet another case that I posted on FaceBook yesterday, and have been speaking to @fehervaria and others about. My case pertains to bad 1.44MB SuperDrive heads. That problem has nothing to do with Zero Track or Motor misalignment. In my case, I know that to be true because I removed the "bad" head unit and also removed the "good" head unit from a different 1.44MB, installing the "bad" into the "good drive." That resulted in that previously good drive becoming bad — putting in known good disks caused the head to move slightly but then the Mac quickly ask me to Initialize the disk. Putting the "good" head unit into my "bad" drive made it into a good drive. That test provided 100% proof that my problem is not Zero Track or Motor misalignment.

I should add that the previous owner of my bad 1.44MB SuperDrive apparently had moved the upper head up too high, which is a big no-no. There were two pieces of evidence which proved that happened in the past:

1. The ribbon cable which connects to the main board in the back and which fits into the black, back-side groove inside the head unit, was complete pulled outside its groove and sitting right next to the other ribbon cable. To pull that ribbon cable out of its groove requires moving the upper head very high.
   
   
2. Using a magnifying glass, the place on the metal piece at the back of the head unit which bends when you lift the head was very slightly bent upward even when the head was down. Checking all my other 1.44MB Superdrive show that place on the metal piece to be perfectly flat. I was able to press down hard on the very back of the head unit to make the bent metal piece go flat, but sadly, that didn't resolve the "bad" head unit's read/write problems.

I've cleaned all my drives and the heads using 100% IPA and fully lubed them properly too. In fact, I cleaned the "bad" head unit many times with IPA and a swab, taking great care not to damage the heads in the process. Nor did I pull the upper head too high. I did multiple cleanings because in the past I had one drive that refused to work until I had cleaned the heads 5 times with a swab and IPA. Yes, that other drive had THAT much gunk caked onto it! Very hard to see too unless you use a magnifying lens.

So because I have a confirmed bad head unit, I am seeking a replacement. No, not an entire drive replacement because that is wasteful. Only the heads are bad. And no, the ribbon cables don't appear to be broken either, although I didn't fully disassemble my "bad" head unit.

All said, some floppy drive problems don't necessarily pertain to the lack of cleaning or a Zero Track Alignment problem or a Motor Alignment problem. There is a category I label: "MYSTERY"

What all this shows is that you really do need more than one floppy drive of the same type which is cleaned, lubed and working good. Then when you have issues with another drive after giving it a full clean and lube, and after examining the heads to find they look OK, you should then carefully swap heads with your good drive before you resort to Zero Track Alignment. That's because Zero Track Alignment is troublesome to do. If your head unit is bad like mine, but you don't know that and just forge ahead with a Zero Track Alignment, you will end up with a bad head unit AND a problematic drive body too.

 

[astron]

Thanks for this post! I just opened up cleaned, and lubed my LC II's drive with @JDW 's video. I thought maybe something was dirty or gummed up but it asks to initialize every disk still. Heads were fine but I swabbed them anyhow. I have a Sony drive with a non-Omron ejection motor (the gear looked fine and there was plenty of clean grease so I'm not worried). What's even weirder is the system hangs when trying to initialize any disk in the drive, and I have to cut the power and manually eject the drive.

I don't have another 1.44 drive on hand to swap heads with...so what replacement 1.44 meg drives are compatible with the LC II?

 

[JDW]

I am the furthest thing from an expert regarding the LC one, two, or three series because I’ve never owned one. But based upon what I’ve seen, some of those machines used manual inject floppy drives while others were auto inject. Those two drive types are quite different.

 

[astron]

It's probably auto inject, because it's model number MP-F75W and it's from before Apple added the little notch beneath the disk slot in the plastic.

 

[JDW]

....what replacement 1.44 meg drives are compatible with the LC II?

For the LC models that use the auto-inject drives (with the skinny disk insertion slot in the plastics which looks like an SE or SE/30, not like a PM6100), most any of the F75W series should work, including MFD-75W-01G and MFD-75W-02G.