Floppy drive head ribbon cable broken

darvil

New Tinkerer
Jun 14, 2023
4
1
3
Hello all, recently I got my hands on a beautiful Mac SE/30, and I've been giving some maintenance to it. Unfortunately the floppy drive didn't seem to work. After looking at it, i found out that the ribbon cable of the bottom head was broken, as seen in this image:

IMG_20230608_1514342.jpg


I was wondering if anyone would have a suggestion for this kind of problem. For now I am going to attempt to solder them back together, but I am not sure if I will be able to with my current equipment, since this seems to be way more finnicky than soldering some board components 😅.
If I'm not able to fix it, would I be able to find some replacement? Are heads of the same type a more common piece among different models of floppy drives, or does this floppy reader only work with this specific heads? My experience with this devices isn't very broad, sorry.

Thank you.
 
Nov 4, 2021
126
98
28
Tucson, AZ
Congratulations, you have a super rare after market 400k drive conversion! :)
My inclination for a hail Mary repair would be to butt the pieces back together and bridge the cut with copper tape, and then try and cut the gap between the traces out of the tape without making things worse.
There's also Z-tape which has been used for connecting LCD screens in calculators because it only conducts along 1 orientation. One long strip goes between the whole row of pins on the LCD glass and the PCB and instead of shorting out everything and letting the magic smoke out it connects the traces on the PCB to the pads on the LCD. Something similar might work for the flex cables if you can scrap off a little plastic insulation and squeeze them together somehow without interfering with the moving parts. Z-tape might distort the signal too much to be usable for a disk head though.
Maybe someone rescued a pair of heads from a drive where all of the moving parts had rusted into a solid block, that'd probably be best.
 

eric

Administrator
Staff member
Sep 2, 2021
941
1,542
93
MN
scsi.blue
If I'm not able to fix it, would I be able to find some replacement?
Do you have the exact model number of this drive? I have a stack of bad floppy drives about 5ft tall, I might be able to find one with that cable/mechanism intact. (free for shipping costs)
 

darvil

New Tinkerer
Jun 14, 2023
4
1
3
For now I will attempt to bridge the gap between the two pieces of ribbon cable with some copper wires and some good hand pulse. Hopes aren't very high though! But it's worth trying.
Do you have the exact model number of this drive?
Yeah, it seems to be a model MP-F75W-01G, or at least that's what it says on the sticker at the bottom. (On top of the disk rotation motor), as seen here:
1686918062953.jpg

Would be awesome if you happened to have one lying around! Thanks.

I will give an update after I (hopefully) finish the repair.
 

darvil

New Tinkerer
Jun 14, 2023
4
1
3
Update here! :) As expected, that was a failure. There's still some hope, though; I may try Lumines' suggestion of using copper tape, after I get some. Thanks again for the help!
If in the end I'm not able to get it working, that is fine. I'm getting a BlueSCSI in a few days, and I'm very excited for that!
 

darvil

New Tinkerer
Jun 14, 2023
4
1
3
Hello, after investigating a bit further, I have found out here that three floppy drive models seem to be perfectly interchangeable. Those being:
  • MP-F75W-01G (Mine)
  • MP-F75W-11G
  • MP-F75W-12G
This information may help on finding broken drives :)
Seems like the 11G model seems to be a bit more common.
Thanks and sorry for creating more activity on this post with updates.
 
  • Like
Reactions: eric