cursed floppy disks

[Z3k]

Today i spotted a nice Amiga600 at a flea market. My strategy with all 8-16 bit computer equipment i collect is the same; i ask "how mutch for that strange keyboard?". 10 euros. With 20 foppydisks, two joysticks, psu and mouse. Lucky day.
When at home i tried almost all the disks(nothing original apart from the Workbench disks) and the all worked!! Lucky day. Now i digged my old floppies and took a few i wanted to check and redump in adf. Quickly dusted off a couple of them and.. the first two worked!! Lucky day. But.. the third i inserted seemed corrupt, same for the fourth and the fifth and so on; the driver seems not to be able to read the bootblock. Ok, they are 20 years old digital medium, shame i had some sources and things i'd like to recover. After that i reinserted some of the disks that come with the 600, the same disks that worked like a charm 15 minutes ago and.. no way to read them, same problem, same bootblock check and again the kickstart screen. I tougth it might be a bootblock virus from the old days so i powered off the 600. After a few minutes i inserted another five disks from the previously working pile and.. no luck at all. I dusted off the floppy drive but still no luck. So i'm asking for some help; what can i do now? is it a coincidence or do some cursed floppies exist?

[Cymru]

Clean the drive heads.

[psygnosis]

Deffo clean the heads

[prowler]

Clean the drive heads and check the third and subsequent old floppy disks you inserted in the drive for mould growth - especially if the drive made a squealing noise when spinning any of those disks.

[lesta_smsc]

All I can say is you got a real bargain!

[Z3k]

I managed to clean five of my floppy derivers and three restarted working!!! I must confess i had 7 Amigas since 1990 and never cleaned a single head before. Regarding the disks i'd want to recover i assume it's definitely a moulding problem
Thanks for your precious advices.

[prowler]

Originally Posted by Z3k

I managed to clean five of my floppy drives and three restarted working!!!

Well done! That's not a bad ratio for a first attempt. Maybe the others will revive with a few more tries.

Originally Posted by Z3k

Regarding the disks i'd want to recover i assume it's definitely a moulding problem

Yes, I'm afraid it's inevitable when floppy disks are stored in less-than-ideal conditions.

However, if you really must recover them, you can try to remove the mould using isopropyl (rubbing) alcohol applied directly to the recording surfaces of the disc with a lint-free cloth.

You will have a far greater chance of success if you break open the disc enclosure and remove the disc for cleaning, then replace it afterwards. This minimizes the risk of contaminating or wetting the tissue layer inside the enclosure and allows you to make sure that all the alcohol has evaporated before replacing the disc.

Keep the alcohol from wetting the area close to the steel hub at the centre. It is attached to the disc by means of a ring of double-sided tape only, and the alcohol may weaken the bond.

[Cymru]

When the floppy part of the disk is removed, don't use alcohol for the mold, rather it dissolves and washes away better with warm soapy water. Alcohol is better for the drive heads.