 I have this old floppy disk drive. It is a Panasonic JU-475, I believe. Yes it is. A 5.25 inch floppy disk drive dating from who knows when. It takes these 5.25 inch floppy disks. I'm using this as part of my flux engine project which is a cheap and simple USB floppy drive interface which you can use to read and write old formats. I've got two of these. One of them is here. The other one is inside this drive enclosure. It's here and I'm just using that as a power supply so it's occupying way too much space in my workbench at the moment. Both of these drives have failed in the same way. I have in the past tried to fix this by replacing some of the capacitors and it didn't work but it's been suggested to me that the problem is probably caused by a dirty screw on the head movement mechanism and hopefully if I clean that it should all come back to life again. So that is what I'm going to try to do today. I have to have a working 5.25 inch drive in order to test 5.25 inch disks. I mean I've got to make it work somehow. I have been trying to find another working one but they're surprisingly hard to find these days so cleaning this is probably the best option. But first I'll demonstrate the problem. So here we have the flux engine board powered on. So we plug in the drive and we power the drive and that causes the flux engine board to restart which then causes it to seek to zero which is why the head just moved. Okay and it's shown up on my laptop over here where you can't see the screen and I should be able to use the flux engine command line tool to make it do a head movement. Yep and you might be able to hear that is not a good noise. So I'm going to take this apart and try and give it a clean and see if that makes a difference. Alright so I've turned everything off and cleared some space to work in. So the first thing you need to do is to remove the cage that protects the electronics. As I said I've had this open before so I know roughly how things work. But I don't recall how much of it I will have to dismantle in order to get at the screw which is here. I think I probably want to take the main board off. But anyway you can see here the works. Here's the mechanism for holding the disk in place. Here's the top head. This is part of the hub that holds the disk in. If I insert a disk this then frees it up so I can rotate the lever. That will cause the head to drop down into place and touch the disk. There's a head on the other side that comes up as well. This clamps on to the middle of the disk. In fact with these 5 nacautions drives when you push the disk in it will start spinning the hub. So that when you press the lever down it will self-center on the disk. So you should only ever insert disks into these drives when they're turned on. Otherwise the disk won't be centered and it won't work properly. The head itself is on this slideable assembly. It's connected here to the drive screw and there's a step motor in there that rotates the screw. The step motor rotates and that causes the head to slide back and forward on its rails. There's a rail there and there's another one in there somewhere. But the step motor is under this and here's the screw. So yeah I am going to have to take this off. Be really careful dismantling these because if you undo the wrong thing you will mangle the alignment of the drive and you need to specialise the equipment to fix it. I've actually done this on another drive and I'm trying to bodge together the appropriate stuff to let me get it back into operation again. Because it's a rather rare drive and difficult to replace. So I'm unplugging all the connectors from the PCB. This is a fairly late model drive which means all the work is done in a single chip. So the PCB is small. There's power, bus interface, all the connectors for the things that make the drive work and not really a lot else. And here you can see the step motor and the screw thread and that has actually exposed everything. So as I rotate the drive screw you can see the head move. That is a bit stiff actually so that could well be the problem. But I don't know whether the problem is the bearing of which there is one in the motor and one here or gunk in the thread. But we're going to have to clean as much as possible. Here are the screws which if you undo them you will wreck the drive alignment. You can just see they're actually slot so this piece can move backwards and forwards. And that controls the alignment of the head with the tracks on the disk. It's important that when this thing moves the head to what it thinks is track 40 it actually has to line up with track 40 on the disk. Which requires precise calibration. So not touching those. Okay let me... I want to remove this screw before it gets lost in the works. Try and remove this screw. Why is that not coming out? There we go. So I've got some solvent, got some IPA here and a sort of different types of contact cleaner. I think I will actually go and grab a old toothbrush because I think that will help too. So one toothbrush hopefully toothpaste free. Grab a cotton bud and let's soak the thing down with IPA. This is the alcoholic kind not the other alcoholic kind. At this stage I just want to try and get it wet. Stuff is coming off. The other thing that's important, yeah you can see it's actually clean on top. But not on the bottom. The other thing that's important when using toothbrushes like this is always distinguish between the ones you use for your teeth and the ones you use for cleaning equipment. Okay I think that's actually done that end so let's just wind this down. Now we have to do the other end. I also want to clean the bearing somehow. Don't really have very good access to it. We're trying to take more of the driver part. If this was in a dusty environment like my house, the toothpaste brush here is going a really nasty color. That would be grease rather than dirt. If this was kept in a dusty environment and dust got stuck to the lubricant then that would definitely have a bad effect on the amount of friction. I'm not sure if it's any less stiff. Grab another cotton bud and just tack that bearing. So I've given the screw thread a good clean. It's possible that the carriage itself, which is here, needs cleaning and lubricating, but I can't take that off without wrecking everything. The other thing that's possible that needs cleaning is the bearing in there. You can actually see the back of the bearing from this side. Which is trying to get that on camera and in focus. Which is in there. And if you watch while I rotate the drive screw by hand, it doesn't actually go round. Which means that the inside of the bearing is not coming all the way out through that piece of metal. I've also taken the opportunity to give the heads a bit of a clean since they're exposed and I have a spare cotton bud. That's always worth doing. So I think that I now need to go and get the lubricant and try applying it and seeing what happens. Well, here is the lubricant. I've never actually worked with this stuff so I have no idea what I'm doing. But I'm going to daub some on the cotton bud and then see if I can work this into the works. This is an interesting green colour. So put a little on the screw thread and then wind that and now that this side of the thread is exposed, put a little there as well. And also try and get some into the bearing. Okay, I think that is all we need. This stuff is thicker than I was expecting. It may not be the right kind of lubricant. Anyway, we now wind this backwards and forwards. It doesn't feel any lighter, I have to say. The other thing, of course, is to lubricate and clean the rails, which I totally forgot about, which is here. That is as dry as a bone. Put some lubricant on and then wind it again. Ah, that is suddenly easier. So maybe just the rails got dry. I don't really like the grating noise it makes. It's easier in this direction than it is in the other. I can't actually think of anything else to do. I mean, I've greased the rails. I've greased the mechanism here. I can't get at the bearing that's inside the motor. So I suppose it's just put the PCB back on and see what happens. Has this made any difference? Remember where everything goes. That plugs on there. That goes through this little slot here and plugs on here. These all go into the little notches provided. So that plugs on like this. At least this thing is nice and easy to maintain. That goes through that little notch there. Here's a homing thing and this plugs on like this. I hope. And finally the LED connector goes on here. And we do the screw up just to hold it in place. The other screw holes are part of the cage. So when I put that back on it will hold the PCB into place rather more securely. If I can make the screw go in. So the cage will go on, yes like that. These wires need sucking in out of the way. Yep, that exposes the test points, the jumpers and so on. So now I need to get all the wiring out and hook it up again for testing. Okay, here we go. So I tell it to seek to the end of the head. It is a much better noise. And it does seem to be doing it reliably. Okay, let's try inserting a disc like so. And if I tell it to read, it's a DFS disc. It's now reading and decoding the contents of the disc via the flux engine onto this laptop here. Which is, by the way, a repurposed Chromebook with an ARM processor in it. So it's not particularly powerful. And watching the log, which you can't see because it's off camera. It looks like it is working perfectly. Tastic. So this is now working, which is great because now I can, you know, do stuff with five necrotrant drives. I know somebody with a X68000 that needs a way to write discs. So this is the obvious option. I will fly getting close to the work. I will swap the two drives and clean the other one in the same way. I suspect that the main thing that made a difference. Yep, that just did a perfect read. Excellent. I suspect the main thing that made a difference was lubricating the rail. But I will give the lead screw a clean two because, you know, I might as well since I have to disassemble it. But that is a success. I know this is not a terribly exciting video, but it's nice to have something that's short and actually works for a change. So I hope you enjoyed this video and please let me know what you think in the comments.