Disks getting ruined again - AT this time

[SpidersWeb]

Let us know how you get on.

My "hail mary" is wet cleaning disks still, but I press down on the head slightly (no seek, disk spinning), I don't usually mention this because it's a bit rough.

 

[SomeGuy]

At least a PCjr 5.25" half height drive should be easy to remove and inspect. Unlike some crazy Japanese 3.5" laptop drives .

I've worked on some drives before that had piles of brown oxide gunk like chuck described. No cleaner disk would make a dent. Also drives with chipped and mangled heads. No cleaner disk can fix that.

 

[barythrin]

I've always wondered this but with the cleaning kits they come with some solution that isn't always mentioned what it contains (probably just isopropyl or denatured alcohol) but does that stuff expire? Do you all use the same solution or just toss that and refill it with something else?

Also I recall an older coworker at my last job (we fixed everything we could ourselves being a tight budget state agency) regarding cleaning printers at least he swore by only using denatured alcohol and not isopropyl because he said isopropyl would dry out the rubber on the rollers (laser printers). Is that a true concern? Given if you're not cleaning something with rubber you'll be fine but I always wondered about that cleaning around anything with a rubber drive belt.

 

[Stone]

I've always wondered this but with the cleaning kits they come with some solution that isn't always mentioned what it contains (probably just isopropyl or denatured alcohol) but does that stuff expire? Do you all use the same solution or just toss that and refill it with something else?

I don't know what the kit(s) came with originally -- that was over 20 years ago. But when the applicator bottle is empy I refill it with iso and have been doing this for over 20 years with great success. Denatured alcohol by definition, contains additives, e.g., methanol, isopropyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, and denatonium.

 

[Chuck(G)]

My big bottle of Xerox CX-85 cleaning solution says "Fluorocarbons, Isopropyl Alcohol" in big letters on the label.

I assume that they mean TF with isopropanol, which would be very logical.

 

[Malc]

I've still got an old RS Floppy Disc Cleaning Kit from many years ago, It came with 2 cleaning solvent aerosols not to mention the Jacket and pads. To quote from the can it contains " Proprietary blend ( azeotropic ) of iso-propyl alcohol and trichlorotrifluoroethane. " must of had it 20 + years.

 

[Stone]

I just found another little, unopened bottle with another cleaning kit that lists the ingredients as: isopropylalcohol, alkalai, acetone, carbide, free acid and water.

 

[modem7]

Also I recall an older coworker at my last job (we fixed everything we could ourselves being a tight budget state agency) regarding cleaning printers at least he swore by only using denatured alcohol and not isopropyl because he said isopropyl would dry out the rubber on the rollers (laser printers). Is that a true concern?

It is a concern. Where I worked, we used a dedicated platen cleaning solution, which I think also claimed to partially rejuvenate the rubber.
From memory, the platen took a while to fully 'dry'.

 

[Chuck(G)]

Yup, you can refurb dry hard platens with a mixture of xylol and oil of wintergreen. It's called "Rubber Renu" and it does the job--and smells nice too.

There's a word you don't hear much "azeotropic"--why you can't distill a mixture of ethanol and water and wind up with 100% ethanol. The weird part is that I knew what "azeotropic" means--and I have no idea why--or why I can never find my glasses...

 

[offensive_Jerk]

So I took the machine apart and pulled the drives. Walgreens doesn't sell throat swabs or 99% isopropyl Alcohol.

Since I only have normal sized Qtips, I pulled the PCB back on the floppy drives so I could access the heads and cleaned them with a Qtip with the floppy cleaning solution that comes in the disk cleaning kits. The 1.2 drive seems to have been fixed as it reads and writes fine so far, but the 360K drive is still wrecking disks.

When formatting a diskette, it only formats to 179,712K, even though it says "formatting 360K" when it starts. And, its still carving rings in the disks. I made sure these rings weren't there when I started.

What's going on with this thing? I took the same disk, wrote an image to it with dskimage on the 1.2mb drive and it was fine. Then did the same procedure on the 360k drive and it spits out tons of errors (on a 360k diskette both times.)

I'm going to put a qtip to it again, but in the meantime, what can I do??

Using dskimage

 

[SomeGuy]

The second head (the top one) on your 360k drive is physically damaged. You will need to replace the drive.

The 180k format is a result of DOS thinking it is now a single sided drive.

 

[offensive_Jerk]

The second head (the top one) on your 360k drive is physically damaged. You will need to replace the drive.

The 180k format is a result of DOS thinking it is now a single sided drive.

I was afraid of that. I was hoping it wouldn't need to be replaced since I wanted the AT original style drives in it. No easy fix for it, huh?

 

[SomeGuy]

As a last ditch resort you could go in there with your finger and see if you can scrape anything off of the top head with your fingernail. But the top head is probably chipped or scratched. Either way, if that were my drive I wouldn't trust it again.

 

[Chuckster_in_Jax]

Years ago I remember hearing that some R\W heads had a glass coating on them. Warnings were made about shipping these drives without a cardboard insert or floppy disk to protect the heads. If the heads contacted each other in shipping it would crack or chip the glass coating. If that is the case, then no amount of cleaning would cure your problem.

BTW: Wal-Mart sells the 99% Isopropyl alcohol. Other pharmacies should too.

 

[Stone]

The regular drug store variety, 70%, works just fine. I've been using it for 25 years with excellent results.

 

[Chuck(G)]

I'm a bit careful with isopropanol, because it almost always contains water.

Drugstore isopropyl tends to be the water azeortope--no more than 87.9 percent alcohol. Methanol, on the other hand will be nearly 100% alcohol--it doesn't have a water azeotrope. Paint-store ethanol (used for shellac thinner) is usually about 95% ethanol--water in a shellac mixture can lead to a cloudy finish if it's excessive.

Tetrachloroethylene, which can also be used to clean heads, has no water in it.

 

[Chuckster_in_Jax]

Looks like I was wrong on buying 99% Isopropanol at Wat-mart(It's only 91%).
I do have some 99% at home and it is used at the company I work for now. I generally like using Methanol over Isopropyl because it dries faster.
I would avoid any chlorinated solvents like Tetrachloroethylene since they are known carcinogens and damaging to the environment. The EPA hates them.

It amazes me the nasty solvents you can get at a paint store, including Methyl Ethyl Ketone and Toluene.

 

[Chuck(G)]

Be sure not to have anything dry-cleaned! Perc is still the solvent of choice for that.

By far, the best solvent for head cleaning was Freon TF (R-113)--now banned since the 90s for ozone depletion potential. HCFC-141 was offered for a time as an alternative (I still have bottles of KyRead where it's used as the vehicle) but that's been banned as well. HCFC-225 (AK225) is scheduled to be banned on January 1, 2015, so stock up--not that it's inexpensive to start with.

Interestingly, a suggested substitute for HCFC-225 is Trichloroethylene, which is really nasty stuff, particularly when encountered as a soil and water contaminant. I expect that the EPA will get around to banning that one also.

As far as tetrachloroethylene (perc) goes, the jury is still very much out on its property as a carcinogen.

Would that the EPA take the same attitude on CO[sub]2[/sub] as it does on fluorocarbons.

I've cleaned stubborn heads with acetone--but be careful--it can murder plastic.