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:
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.
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:
- 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.
- 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.
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.