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What can cause an external superdrive to fail?

pcamen

Well-known member
In the last couple of weeks I've used my Applesauce to convert quite a few 3.5" floppies ... 400k, 800k, and 1.44M. It worked well. I even broke the drive eject gear, replaced it, and it kept on chugging just fine.

But a few disks I did this week have me scratching my head. They came with two different Farallon Star Controller. One of them had clearly been used before (but was in good shape) and the other two were in a sealed envelope. When I tried to read them with the Applesauce, all three had many bad sectors.

On in particular, I kept retrying the bad sectors over and over and it would correct a few each time, until I got down to the ones it could not correct.

I tried cleaning the drive head, and the next time I tried to read the same disk, it was much worse than it had previously been.

For giggles, I tried reading the disks using my LC 475. Here’s where I am confused. The LC 475 had no trouble reading the disks and making images of them, all with no errors. I even tried running one of the programs that the Applesauce said had errors and it seemed to run fine.

When I tried the external drive on a Iici, it found the same disks unreadable whereas the Iici internal drive didn’t have issue with them.

I am using a Superdrive in an 800k housing (because true external Superdrives are very hard to come by). I don't suppose that creates some strange issue does it? All three disks are 800k disks.

I haven't tried replacing the Superdrive with another one yet (it is a bit of a PITA to get the drive in/out of the external housing, and I have to attach a rotation sensor for the Applecause to a new one) but that's probably my next step.

Anyone know what can generally go wrong with external drive electronics or internal drives that might cause issues like this?
 

pcamen

Well-known member
Well, it's definitely the floppy drive. I pulled the one out of my LC 475 and it works fine with the Applesauce. Still wondering what can cause them to go bad.
 

markyb86

Well-known member
hmm, I put my superdrive into an 800k housing too, and you know what? the SE it came from won't boot with it connected externally.
I doubt it but maybe the cable in the housing is wired differently than the internal connector? Strange coincidence.
 

waynestewart

Well-known member
I’ve original superdrives and upgraded 800k drives. The only differences are LED colour and an extra metal shield. I happily use them interchangeably.



Other than insufficient cleaning then my next thought is dried up lubricant not letting the disk go 100% of the way in.
 

pcamen

Well-known member
Well no clue on the original drive and why it is not reading properly. I tried cleaning the head again to no avail.

I tried a second Superdrive and it is 100% dead, the Applesauce can't talk to it at all.

I found a third that works that has a dead eject motor; dead as in doesn't do anything at all, gears are fine. I replace the eject motor assembly with the one from the first one and now it works fine.

I never knew that, other than needing a cleaning and lubrication, there could be many more ways a floppy drive could die.
 

waynestewart

Well-known member
I use superdrives quite a bit and have only had 3 issues. Dirty heads, dried lubricant and dead eject motor. In one case the dried lubricant let the disk go in but the heads weren't making god contact with the disk.
 

Franklinstein

Well-known member
Some of these drives do have electrolytic caps on them. They may need replaced.
Also, head tension can reduce over time to where they heads don't contact the disk properly. Or your stepper motor can be slightly out of line. Either of these will generally cause problems with multiple disks, not just one or two random disks, so I wouldn't suspect this unless the problems are consistently with disks created at factories/on other computers but not on disks formatted with this specific drive.

Auto and manual-inject floppy drives have different cabling requirements, if you didn't know. Most pre-1993ish Macs won't play nice with manual-inject drives and most post-1995 Macs won't play nice with auto-inject floppy drives. There were a handful of Macs in the 1994 range (mostly late-model '030s, '040s, and NuBus Power Macs) that could use either one interchangeably. The problem is something about one of the pins being used on one type but not the other, similar to the very early 400k/800k drives with their yellow or red-striped cables. You may be able to make a custom cable to get around the problem on some machines such as when modifying a Color Classic (auto inject) to accept a 5400 logic board (manual inject).
 
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