Repairing bad disks

[B14ck W01f]

What is the best way to repair defective floppy disks? Sometime last year, I managed to get a copy of New Zealand Story from Amiga Heaven. At first it wouldn't boot at all, but after days of inactivity, I got as far as the loading screen then I receive a guru mediation. And this always happens from now on. Would I have to use DiskSalv or some other software I never heard of? Also, there is a scraping noise that can be heard when it loads the game. Will this sound damage the internal floppy drive in the future?

[dlfrsilver]

your disk has mould on it. You need to open the disk, and use some alcohol with a coton eye cleaner (1 with alcohol, not too much of it, and 1 dry to dry the disk surface).

Then you should be able to get the disk to work if the mould has not penetrated too deeply inside the coat.

[BarryB]

Slide the disk shutter open and slowly spin the disk a full revolution, check both sides for anything sticking to the surface then do as dlfrsilver says and clean the surface through the shutter hole, I don't like breaking open disks! Chances are that whatever is stuck to the disk has now gummed up your drive heads too so you need to clean those as well, it could also score the disk surface and could have damaged that so once cleaned check the surface again!

Once cleaned, if you have x-copy, stick the disk in DF0: and click 'checkdisk'. You should see the very first track as a red '2' (copylock track) and the rest should be all green '0' meaning it's read the disk without errors!

[Amiga1992]

The noise is "lethal" to your floppy drive. That is mold as dlfrsilver mentioned. Once you hear it IMMEDIATELY remove the disk from the drive. I have ruined many drives with this shit.

Crack open the disk and clean it as he said. Personally I just used water, not alcohol. Then place it in a NEW case, the old one probably has mold in it and you shouldn't use it again. You shouldn't just try to clean from the disk shutter because the mold in the case will get back on the floppy surface.

I restored MANY floppies with this method.

[BarryB]

If you're not bothered about the disk then breaking it open is fine, but breaking the case ruins the original and collectors don't like that if you sell the game on!

It would be much easier to write an IPF back to a blank disk and use that than ruin originals! I used to break open disks that had some stains/debris on them but couldn't stand the damage it does so I clean through the shutter now and have had no issues dumping the cleaned disk in my Kryoflux and creating IPFs of supported dumps in disk-utilities. Granted I only clean disks when needed and only use the originals to get a Kryoflux dump, but an intact original is still valuable

[ReadOnlyCat]

Water is definitely not a good idea in the long term since that actually helps the remaining microscopic mold to grow.

You want to use a mixture of peroxide water (0.03% peroxide) and isopropyl alcohol (>70%) in approximately equal quantities.

The alcohol will kill the active mold but is unable to kill the spores by itself, only the peroxide water can do that which is why you want to mix them.

I had to throw about half a dozen originals because of that and it is really hard to get rid of if you do not fully swap disks to a new non-infected enclosure so do not skimp and just assume that a simple cleaning session is enough. The old soft inner lining of disks cannot be safely reused as it is full of mold spores.

Also once the alcohol + peroxide mix has dried on the naked disk, you can use a hair dryer at very low temperature to dry it and ensure that no water remains on its surface. Any remaining water even if invisible to the naked eye will be used by mold to grow again.

[Amiga1992]

Originally Posted by ReadOnlyCat

Water is definitely not a good idea in the long term since that actually helps the remaining microscopic mold to grow.

It's not a problem if you dry it thoroughly. I disposed of those discs anyway, it was a one time solution to just digitally rescue them, I had no need for the discs after I dumped them.

[rare_j]

How does the mould get onto the disks in the first place? Are they stored in a slightly damp environment? Would disks always stored in a plastic disk box be safe?

[dlfrsilver]

Originally Posted by Akira

It's not a problem if you dry it thoroughly. I disposed of those discs anyway, it was a one time solution to just digitally rescue them, I had no need for the discs after I dumped them.

Akira, the water is clearly not the liquid to pour on the disk surface.

the inner cleaning surface must be desinfected with alcohol.

Just for the record, i tried to read 8 months later some disks i cleaned.

They read exactly like when i cleaned them from day 1.

[BarryB]

Similar to me, disks that had mold/dirt cleaned off them are still reading many months later but they are now stored in their box on a shelf indoors and not in some damp garage/cellar ready to be sold on ebay

[dlfrsilver]

Lol xd !

[Amiga1992]

Originally Posted by dlfrsilver

Akira, the water is clearly not the liquid to pour on the disk surface.

No, it isn't clearly, I keep telling you it worked for me. That's all. Not saying your method doesn't work, just adding one. Water worked for me. Does it work again after some time? I DON'T KNOW because for mold reason I disposed of the cases which probably have lots of mold stored in the fabric that protects the discs from plastic.

Off the counter alcohol will leave residue though, if you go the alcohol way, I'd get isopropyl alcohol.

[ReadOnlyCat]

Originally Posted by Akira

No, it isn't clearly, I keep telling you it worked for me. That's all. Not saying your method doesn't work, just adding one. Water worked for me. Does it work again after some time? I DON'T KNOW because for mold reason I disposed of the cases which probably have lots of mold stored in the fabric that protects the discs from plastic.

Off the counter alcohol will leave residue though, if you go the alcohol way, I'd get isopropyl alcohol.

"It worked" is obviously not taking into account the fact that spores are still present on the disk and likely inside. Any airborne humidity will regrow these spores over time.

So, yes, it seems to work on the surface but the root cause of the problem is still there.

Peroxide water is the only way to kill spores reliably.
Isopropyl alcohol does not kill spores, it only kills the growing mold.
Both are needed for a durable cleanup.

[B14ck W01f]

Thanks guys for getting back to me about this. Appreciated.

[markpjd]

Originally Posted by rare_j

How does the mould get onto the disks in the first place? Are they stored in a slightly damp environment? Would disks always stored in a plastic disk box be safe?

Not sure, seems to be some kind of microscopic mold spore.. I always thought mold needed a food source, but I don't know the science behind it all. What doesn't make sense is that I had some disks stored in almost perfect condition and they still failed due to mold. On the other hand, I think it may be brand dependent too, as some disks seem more resistant or durable than others.

[ReadOnlyCat]

Originally Posted by markpjd

Not sure, seems to be some kind of microscopic mold spore.. I always thought mold needed a food source, but I don't know the science behind it all. What doesn't make sense is that I had some disks stored in almost perfect condition and they still failed due to mold. On the other hand, I think it may be brand dependent too, as some disks seem more resistant or durable than others.

As long as there is more than 50% humidity in the air, mold can grow on a substrate. Unless you actively control humidity there are always moments where humidity will be above 50%.