The 91% solution would be the same found in the cheap
cassette tape cleaning
kits I assume.
I believe so, although I have a spray can of what claims to be 99+%
propan-2-ol that I use for head cleaning.
The reason I brought this up is because a few days ago I started backing up
some vintage Mac software on my 840AV 68k Mac and it had a problem with a
few disks, so I switched to my IIfx (same type of drives) and it read those
disks no problem. I figured that the 840av disk drive just needed a bit of
cleaning since it has been reliable before the last incident. I don't think
True story (although I am ashamed to admit it). I was sorting out a
Commodore 8250LP (slimline model, double sided drives). And I could not
get a reliable read signal.
I checked all the components in the head amplifier, the head switching
diodes, the head select signals, and so on. I then remembered to clean
the heads. Worked fine after that...
-tony