Which OS? My USB floppy drive just started doing something similar to this a couple of weeks ago, on my main PC with Windows 10. But the USB floppy drive works fine on one of my Linux laptops.
The disk I'm testing with is a Win98 bootdisk that works fine in all floppy drives on old PCs, I've tried several other disks as well though.

From what you've described, you may have a different problem. It sounds like the alignment of one drive might be different from the other. Probably best to test with another floppy drive so you can determine which of the two has bad alignment.

I don't know, but the usb floppy drive needs might just be dirty. reading old floppies can have that effect I heard. Dirt, dust and oxide you know.

Personally I don't think it is alignment if you fail to write on the usb drive.

Actually tried to copy something similar the other week but I ended up giving up and burning a cd with an usb Lenovo dvd writer..

Many USB floppies only read standard 1.44Mb floppies. Others can read both standard 720Kb an 1.44Mb.

Excluding special hardware like Kryoflux, I don't know any floppy that can read not standard floppies (i.e.: floppies with 10 sectors/track or with odd sector numbering). So don't expect reading copy protected disks.

Thermalwrong wrote on 2021-10-06, 21:06:

Which OS?

I tried both Windows 10 and Windows 7.

My USB floppy drive just started doing something similar to this a couple of weeks ago, on my main PC with Windows 10. But the USB floppy drive works fine on one of my Linux laptops.

Mmm, I have an old Linux laptop I could try, thanks for the idea.

From what you've described, you may have a different problem. It sounds like the alignment of one drive might be different from the other. Probably best to test with another floppy drive so you can determine which of the two has bad alignment.

Given that my old Win2K PC can read all floppies I feed it, but the USB floppy drive can't (even official disks), I highly suspect it's the USB floppy drive that's off. Weird though, back in the days I never had problems reading any 3.5" floppies. Maybe the USB floppy drive is just botched...

Joakim wrote on 2021-10-06, 21:26:

I don't know, but the usb floppy drive needs might just be dirty.

Well, it's brand new, just bought it.

Personally I don't think it is alignment if you fail to write on the usb drive.

It doesn't fail to write, but what's written fails to read on the Win2K machine.

Zup wrote on 2021-10-06, 21:45:

Many USB floppies only read standard 1.44Mb floppies. Others can read both standard 720Kb an 1.44Mb.

These are all 1.44MB floppies.

So don't expect reading copy protected disks.

I was only suspecting to copy something on a floppy and read it on my old machine 🙁.

JAL

Ok, small update: I tried the USB drive on Linux, but though it mounts, trying to read the floppy hangs the process (drive light constantly on, waiting mouse pointer). So I guess it's the external drive that's not good.

Yeah those external drivers are very cheap. I bought one from aliexpress a couple of years ago and it never worked fine, I had your very same problem.
Then I found there are adapters to use the old floppy drives with usb, since then I use it without any issues with windows 10.

If you want a real USB floppy, there are a few good ones I can recommend.

Dell - These come in both plain USB and also the laptop module type which can be hooked up via USB.

Any of the ones that claim 2x speed. They all use the same drive inside them. (Mitsumi D353FUE or a variant). I had a SmartDisk branded one of these I bought new years ago.. lasted at least 5 years. Then the one day I went to use it and it wouldn't read disks anymore. Come to find out one of the heads had come loose and was flopping around in the drive. Not sure if I dropped it or what happened. Ended up ordering another 2x floppy drive to replace it.

One I cannot recommend for use in Windows 10 is the Sony VAIO models. They will not work with Windows 10.

All that being said, I use a few different drives when making images of 3.5" floppies. Some drives will read some disks while other drives will read other disks. Just because a disk will not read in one known good drive doesn't mean it won't read in another drive.

Nemo1985 wrote on 2021-10-07, 13:02:

Yeah those external drivers are very cheap. I bought one from aliexpress a couple of years ago and it never worked fine, I had your very same problem.
Then I found there are adapters to use the old floppy drives with usb, since then I use it without any issues with windows 10.

That's interesting, since I have a load of old floppy drives in my drawer. What kind of adapters are they? Are they easy to come by?

JAL

jal wrote on 2021-10-07, 14:15:

Nemo1985 wrote on 2021-10-07, 13:02:

Yeah those external drivers are very cheap. I bought one from aliexpress a couple of years ago and it never worked fine, I had your very same problem.
Then I found there are adapters to use the old floppy drives with usb, since then I use it without any issues with windows 10.

That's interesting, since I have a load of old floppy drives in my drawer. What kind of adapters are they? Are they easy to come by?

JAL

Yeah, just do an eBay search for:
usb floppy adapter

They can be had for a bit less than $10 US shipped from China if you don't mind waiting forever and a day for it to be delivered.
If you buy one for around $11 US, then the shipping time comes down.

What I mean is that even if the drive is brand new and you read s dirty disk, the drive can get dirty and stop working.

jal wrote on 2021-10-07, 14:15:

Nemo1985 wrote on 2021-10-07, 13:02:

Yeah those external drivers are very cheap. I bought one from aliexpress a couple of years ago and it never worked fine, I had your very same problem.
Then I found there are adapters to use the old floppy drives with usb, since then I use it without any issues with windows 10.

That's interesting, since I have a load of old floppy drives in my drawer. What kind of adapters are they? Are they easy to come by?

JAL

I bought it from aliexpress, some time ago, do as cyclone3d said, you will get it right.

Depending on the interface of the USB floppy drive, you could directly exchange it with any other normal floppy drive, or it might need a small adapter board, or if you have a laptop floppy drive you could use that. YMMV.

good luck.

In the mean time, I have managed to get a 2nd old PC (but a lot less old than my Win2K one, viz. a Celeron D with Windows 7) up and running, and it has no problem reading all of my old disks, nor does it have a problem exchanging files per disk with the Win2K machine. So I've sent the USB floppy drive back to the shop as defective. Thanks all for the replies.