Floppy drive alignment question

[tanaquil]

I have a stack of floppy drives that need repair. Probably going to tackle it later this summer.

A specific question for today, though: the 1.4 floppy in my IIsi recently failed, making horrible grinding noises (no doubt a gear issue, I'll check it out later). I thought maybe I could replace the floppy with the drive I recently pulled from my Classic, which was working when last started up (not sure how long ago that was).

I had to remove the Classic floppy from its hardware casing and put it in the IIsi casing, since the caddies are very slightly different sizes.

When I tried to install the old Classic drive in my IIsi, the mechanism works perfectly (smooth inject/eject, no bad noises, etc), but every time I insert a known good disk, it whirrs for a while and informs me that the disk is unreadable. 

While it is possible that something went bad while the Classic was in storage (this was the Classic with the exploded Maxell, though I can't see any trace of corrosion on the floppy unit), I'm thinking there might be an alignment difference between the Classic and the IIsi? Or could I have knocked the motor out of alignment while transferring it from one casing to the other? Anyway, I've heard there is a way to realign floppy drives that are out of alignment, but I have no idea how to do it.

Advice welcome! I know of threads explaining how to clean and lubricate old floppy drives, but this seems like a different issue.

 

[bibilit]

Hi, this problem is related most of the time with a dirty head.

All 1.4 drives are the same so there is no problem of alignment.

In the other hand, if your head is dirty, it won't be able to read a good disk.

A dirty head is usually detected by a straight black line in the head, and can be removed with nail remover and a cotton bud.

The dirt can be generated by a bad floppy disk, some sort of vicious circle, the disk will make the head bad, then will make a good disk bad in return...

If cleaning will not solve your issue, you can swap both heads, just two screws and two ribbon cables to remove.

 

[techknight]

the alignment cant drift usually unless the screws behind the stepper motor work loose, or the floppy drive took a tumble/fall. 

 

[tanaquil]

Thanks very much - I don't know why I didn't think of that at once, especially since I frequently clean the heads of the floppy drives I am using to image my dusty old floppies from the basement. I'll have to hook the drive back up to test the theory.

If I ever were to encounter a misaligned floppy drive (for instance, if I had to replace the motor on some of my currently non-functional drives), is there a simple procedure for re-aligning it?

 

[techknight]

You have to verify that its misaligned by formatting a floppy in the misaligned drive. It should be able to format, write, and read its own disks. But another drive cannot. and vice versa. 

If that happens, its mis-aligned. adjusting the stepper motor with a known good disk by rotating it will bring it back into alignment.