When to give up on a 1.44MB floppy drive

[elemenoh]

I've been trying to restore a floppy drive from an SE. The usual stuff like cleaning, replacing grease and replacing the bad eject gear went fine. It would still not read or format disks.

I've tried adjusting the track 0 sensor and stator motor across their range, but haven't seen any improvement.

Disks will begin to format but ultimately fail. There's a noise about 30 seconds in, just before the failure where it sounds like something is rubbing. 

Should I keep tinkering with track 0 and/or stator? Anything else to try? Or does this just seem like it has a bad head and I should move on?

View attachment Bad floppy.m4a

 

[CC_333]

It's funny this came up!

I don't want to hijack @elemenoh's thread (I'll start my own at some point), but I'm facing a similar problem.

I have four drives, three 1.4Mb and one 800k, and I can't get any of them to work.  Mechanically, they're all in good working order, the stepper motors are good, and the ejection action is smooth.  But whatever I do, I can't get any of them to successfully format a disk!  I think they do the same thing as yours: format for about 30 seconds, and then when attempting to verify, it'll stall for a couple seconds, then retract the head and thrown an error.

I've tried a known-good head from an 800k drive (assuming that they're the same), and no change.

c

 

[OsvaL]

I have the exactly same problem with my floppy drive (Sony 1.44 Macintosh Classic) under System 6.0.8.

 

[Papichulo]

im having the same problem with my iici, lc, iisi floppy drives. the more modern ones work like the performa ones

 

[LaPorta]

The biggest issue we are dealing with here is that despite all the wonderful people/resources we have for our machines, virtually no one seems to know anything about the Sony drive electronics. It’s like a huge black box. So, despite being able to fix the mechanicals of it, if something electronic goes out, we have no experienced people to explain things and no schematics to follow. So we all scratch our heads and try this and that, but that’s about it.

 

[OsvaL]

The biggest issue we are dealing with here is that despite all the wonderful people/resources we have for our machines, virtually no one seems to know anything about the Sony drive electronics. It’s like a huge black box. So, despite being able to fix the mechanicals of it, if something electronic goes out, we have no experienced people to explain things and no schematics to follow. So we all scratch our heads and try this and that, but that’s about it.

 You are right. When I was trying to troubleshoot my floppy drive, I left it on top of its bracket without noting it was touching the PCB producing a short. Some electronic component broke and smoke escaped from it. I don't know the specification of the part that broke so I can't change it. If someone has a clue, anything is welcome.

The part is located in Q3.

 

[LaPorta]

I’ll have a loot at mine for you.

 

[rplacd]

The biggest issue we are dealing with here is that despite all the wonderful people/resources we have for our machines, virtually no one seems to know anything about the Sony drive electronics. It’s like a huge black box. So, despite being able to fix the mechanicals of it, if something electronic goes out, we have no experienced people to explain things and no schematics to follow. So we all scratch our heads and try this and that, but that’s about it.

Honestly, I have two Sony drives I'm not using – if someone wants them to take them apart and draw up some schematics, I'd be happy to donate them to the cause. My compact Macs don't need them, I haven't checked them since I found the Macs, and I use a Floppy Emu anyway.

 

[elemenoh]

Update on the problem drive:

First, I'm a dummy and was using a 1.44MB "Superdrive" on an older SE MLB that didn't support it. So at best I'd have been able to only format as double density. I switched out to an SE/30 MLB for testing.

I was originally testing with a disk that had worked fine recently. I tried another disk and after some more adjustment of the track 0 sensor it did successfully format. After tweaking the stator motor it started reading other disks okay.

While the test rig was set up, I tried a couple other problem drives that I previously gave up on. Both started working after adjusting the track 0 and sensor motor as well.

Dead Mac Scrolls recommends adjusting the track 0 sensor until you can get a disk to format, and then the stator motor until it reads other known-good disks. This didn't work in my case. No matter how much the stator motor was adjusted, the drive wouldn't read known-good disks even if it could format them OK.

What did work was adjusting the track 0 sensor until the 'minor repairs' dialog would display for known-good disks, and then fine tune the stator motor. With that method I was able to get each drive dialed in within maybe 5-10 minutes. I hope this helps anyone else in a similar situation.

Also, I burned a drive in the past the same way @OsvaL describes. Since then, when testing, I always put them in their bracket (without screws) to avoid shorts or rubbing stuff against the motor.

 

[OsvaL]

I’ll have a loot at mine for you.

Thanks a lot @LaPorta  I have another floppy drive from a Performa (not compatible with the Classic) I may take the part from its PCB.

 

[chiaki]

currently im try to repair two 2MB autoinject sonys, cause the newer manual-inject stolen of my powermacs doesnt works well without dashing the floppy for inject  :ii:

i have issues cause the upper head is have not the right force on the surface,  also one drive have a broken tiny plastic-wing. how i to fix and re-aligned the mechanics?  :-(

there exist some docs about the older 400k and 800k drives  ( http://www.bitsavers.org/pdf/apple/disk/sony/ ), also bomarc have a schematic for the 2MB sony.

 

[LaPorta]

Thanks a lot @LaPorta  I have another floppy drive from a Performa (not compatible with the Classic) I may take the part from its PCB.

Apologies that I never did this. Being a Q part, it is a transistor. I checked two drives, and both have the microscopic label "BV4" etched into them. That should at least get you started on a search.

Edit: This may be its description: 

https://alltransistors.com/transistor.php?transistor=10630

 

[OsvaL]

Apologies that I never did this. Being a Q part, it is a transistor. I checked two drives, and both have the microscopic label "BV4" etched into them. That should at least get you started on a search.

Edit: This may be its description: 

https://alltransistors.com/transistor.php?transistor=10630

Thank you very much @LaPorta now I can confirm this. I was looking at the sorrounding BV4 transistors and they were connected exactly the same way as the one I burnt. Then I started looking on some high resolution photos I found on the internet and with some Photoshop I was able to make the photo more clear and got to see the BV4 on top of the transistor. Thanks a lot, now I can confirm my suspicions.

 

[mitchkramez]

On my drive, they were labelled B•6 - @JDW helped me narrow things down, but was able to find some 2SB815B6-TB online from a company in the UK. Good to know there are other possible alternatives, the specs on the BV4 just appear to be a bit heavier duty at first glance. the B•6 was very tough to find, but it did fix my drive