5.25 floppy drive maintenance

Last Updated on March 18, 2023 by Dave Farquhar

It’s been a long time since 5.25-inch floppy drives were mainstream. But a lot of them can still work today with a little bit of cleaning and lubrication. Here’s a quick guide to 5.25 floppy drive maintenance.

Cleaning the heads, then cleaning and lubricating the rails is usually all it takes to get a 5.25-inch drive working well. Using the right cleaner and lubricating sparingly is the key to doing more good than harm.

I love my Gotek but it doesn’t help me with my existing 5.25-inch floppy disks. For those, I needed to fix my 5.25-inch drives. Of course, once I got them running, copying any disks I care about over to the Gotek is a great option for archiving.

What you’ll need

You’ll need a Phillips-head screwdriver, some cotton swabs, some 91% isopropyl alcohol, and some kind of silicone lubricant with PTFE (also known as the brand name Teflon), or lithium grease. Cleaning and lubricating a drive will frequently bring a balky drive back to life, and keep a functioning drive functioning well. Today’s better lubricants will cause the drive to operate more quietly than it did when it was new.

Silicone lubricant is ideal because it doesn’t gum up and collect dust. The drive rails don’t have to be super slick, they just need to let the drive head assembly glide freely. After the carrier evaporates, it leaves behind a surface that’s slick enough, but won’t gum up and won’t collect dust.

Usually you’ll need to remove the drive from the case to clean it, unless your drive is in the top bay and the bay is really open.

Also, keep a camera handy (your phone will do). Snap pictures as you’re disassembling and working on the drive. It can help in troubleshooting later, if there are any loose connections inside, whether it was you or the last person who worked on it who unplugged stuff. If the drive misbehaves, pull out the pictures and look for loose wires. Ask me how I know this trick.

Cleaning the edge connector

5.25 floppy maintenance
Start with the edge connector. Almost everyone forgets that.

The first order of business is cleaning the edge connector. Even if it looks clean, it’s probably filthy. If it’s green and corroded, polish it with some metal polish or a U.S. dollar bill. Yes, a U.S. dollar bill is abrasive enough to remove corrosion but not harm the metal.

Even if you don’t see any corrosion at all, clean both sides with a cotton swab dipped in isopropyl alcohol, at the very least. Contact cleaner would be better, but you’re more likely to have isopropyl alcohol on hand, and it does a good enough job. You don’t want dirty contacts interfering with the drive’s operation.

Sometimes a dirty edge connector is the only problem I find with an old 5.25-inch floppy drive. And it’s a really quick and easy fix.

Once the contacts are shiny, you can move on to the next step.

Cleaning 5.25 floppy drive heads

5.25 floppy maintenance
To clean the drive heads, swab them down with a cotton swab dipped in alcohol. Get each head, and repeat until the swabs come out clean afterward.

Cleaning the heads is usually the most critical part of 5.25 floppy drive maintenance.

Before you can get to the heads, you have to remove the protective plate on the top of the drive, if it has one. Most drives had one when they were new, but some of them have lost theirs over the years. Usually they’re held on by four screws. After you remove the cover, you can see the head assembly. Dirt and old magnetic particles from disks can prevent the drive from reading properly, but they aren’t hard to clean.

The condition of the heads depends largely on how much the drive was used. 1980s drives are often pretty dirty because they saw a lot of use. Drives from the 90s that only saw occasional use are often pretty clean.

For cleaning the drive heads, you need 91% or 99% isopropyl alcohol. Here’s how to tell the difference. Dip a cotton swab in some alcohol, then scrub the drive heads. You can’t see the top head, so here’s a rule of thumb to follow. If a swab looks dirty after you clean the top head with it, replace it with a new one and clean the top head again. Repeat the process until you can swab it down with a new swab and the swab stays clean.

The lower head is easy, since you can see it. When the head looks clean, it’s clean enough.

Lubricating 5.25 floppy drive rails

5.25 floppy maintenance
Clean the old grease and dirt off the rails, then apply a bit of silicone lubricant to the rails for smooth operation. Also, if you see a loose connection like in this picture, fix that while you’re in there.

Lubricating the floppy drive’s rails prevents seek errors. If the drive can’t move the heads the way it expects, it malfunctions, so this is another important part of 5.25 floppy drive maintenance. Depending on the drive’s design, you may or may not be able to move the head assembly manually. If you can’t move the assembly, don’t force it.

Don’t spray directly into the drive. That will just dirty up the heads again. Apply it with a cotton swab.

Dip a clean swab in some alcohol and wipe down the two rails. On some drives, the rails are just smooth bars of steel. Other drives may have a rail on one side and a worm gear (a threaded rail) on the other. Sometimes they’ll be really dusty. Other times they’ll look clean, but they still benefit from having the decades-old lubricant removed and replaced. Swab them down until they’re clean. They’re always much dirtier than they look. Once the swab stays clean after wiping it across the rail, spray a bit of silicone lubricant on a new swab, then rub the swab on the rails. Move the head assembly back and forth if you can, to distribute the lubricant. On a drive with two rails, you can push the head back and forth to slide it around. On a drive with a worm gear, try turning the worm gear with your hand to move the head back and forth.

Don’t over-lubricate the rails. It only takes a small amount. In a pinch, you can just leave the rails dry and the drive will work better than it would with old, gummy lubricant on it. But the drive will work more smoothly and quietly with light lubrication.

Checking cable connections and one more thing

While you have the drive out and in the open, double check all the cable connections. It’s unusual for any of them to be loose, but it pays to be sure. In the photo above, you can see how the connector for the LED was loose. Cable connections are easy to overlook; take the extra minute to check them so you don’t have to do your 5.25 floppy drive maintenance a second time.

When I wrote this guide I hadn’t seen this problem before, but sometimes the spindle clamp doesn’t release freely so disks can get stuck in the drive. Here’s how I fixed a sticky spindle clamp.

Exercising the drive

When you’re finished, it helps to exercise the drive soon after to distribute the lubricant around, especially if the drive’s design doesn’t allow you to move the head around manually very easily. Connect the drive to a working machine, configure the drive in the BIOS if necessary, and boot into DOS, ideally. Then insert a disk you know works and run the command scandisk b: /scanonly /surface on it. This will step the drive over the full surface of the disk. I like to run this command several times.

If you don’t have DOS 6.2 available, you can just copy all the files off the floppy disk to a temporary directory to get something almost as good, depending on how full the disk is. Just issue the command copy /y b:\*.* c:\temp to copy all the files. The more full the disk is, the better this works.

This all assumes your drive is drive b. Substitute a: for b: in either command to exercise your A drive.

With this simple bit of 5.25 floppy drive maintenance, you can make your 5.25 floppy work better than it did when it was new. We have better lubricants now than we had in the 1980s. So drives can go longer before they need their next tuneup, and they’ll work more quietly than they did when they were new, which is always nice.

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