Very common problem with floppy drives as they age is dirt and corruptionvon the heads.

First thing I would do is a good head cleaning.

Mu ImageDisk has a pretty good "clean heads" function, where it "scrubs" the heads back and forth on the cleaning disk.

If you don't have cleaning discs you can often make passable ones from paper in a disc sleeve (easy on 5.25", tricky but doable on 3.5" - just make sure you have a suitable cleaning solution (or at least some alchol).

I have already cleaned the heads using a Q tip and alcohol. I just scrubbed them again as hard as I could without breaking them, no dirt came off and it still won’t read the disk.

Qtips can work but you have to be dead-careful not to damage the head mounting.
Very easy to damage on the upper head, much sturdier on the lower head.

Perhaps the drive was knocked intoi poor alignment in the shipping roughness...
Does the head assembly appear at all "lost" (ie: can you fee;/see it move "by hand") - best way to test this is with power off, manually move the stepper to put the head near the middle of it's travel.

Do you have another floppy drive you can try in the system?
This woiuld help determine if the problem is in the drive, or the system.

Or ... do you have another system with a floppy controller and cable (you could probably use the cable from this one).

It would be interesting to know if another system using the same drive also has problems reading sometimes,
and if you make a system disk on the drive in that system, does it work on the Tandy. Formatting a disk on a drive with bad alignment will make a disk which equally bad alignment which should work well on that drive.

Also worth trying to make a single-sided boot disk. As mentioned above, the upper head is more susceptible to physical damage. A single sided boot disk would only need the lower head.
(sorry - I don't even recall if the PC/DOS can do single-sided boots - I *think* some earlier versions can - I can look into this more if this becomes needed)

I don’t have another drive to test it with. I moved the head assembly by hand and it is smooth and moves easily. Nothing else in the drive seems to be mis aligned, just looking at it visually.

When I power it up with the drive cover off and try to boot the ms dos disk, the head assembly does not start moving over the disk, it just stays there, the disk stops spinning, and the screen says “Insert system diskette and strike any key when ready” like I haven’t put a disk in. Other times when I try to boot it says “Boot failure”

CKK86 wrote on 2026-04-05, 22:27:

When I power it up with the drive cover off and try to boot the ms dos disk, the head assembly does not start moving over the disk, it just stays there, the disk stops spinning, and the screen says “Insert system diskette and strike any key when ready” like I haven’t put a disk in. Other times when I try to boot it says “Boot failure”

It normally won't - it should seek to track0, then try to read the boot track - if it can't read that track it will retry a few times then give up.

I assume if you move the head out 1/2 way with power-OFF, then power-ON, the BIOS will seek it back to track0 in fairly short order?

Do you have any other way to boot the system, does it have a hard drive? I'm not famillier with the 1000EX - is it new enough to know how to boot USB?

Yes, it will reset to track 0 when I move the head assembly half way and turn it on. It doesn’t have a hard drive, but it does have a connector for an external floppy drive. Maybe I will need to get one.

If you don't connect the drive at all, does it give you the "insert system disk" message, or a different error?

I'm wondering if the select is wrong... BIOS probably homes the heads on all drives that it can detect to put them all in a known position, and it looks like it's detecting your drive...

On almost all PCs the cable has a twist so that IBM could drive both drive select and motor on independantly for both A: and B:
(standard SA400 FDC interface has only one Motor ON signal causing all drives to come on at once) - It also moves the selects around
so the select for 1(A:) becomes 2(B:) after the twist. This is why both drives on a PC must be jumpered as 2 (B:)
- I think IBM also didn't think consumers could move a jumper, and didn't want their dealers to have to stock two different drives.

But... perhaps Tandy doesn't follow that convention and follows "normal" which is 1 for A: and 2 for B: (assuming you number the selects from 1) - a particular drive might show 0-3 instead of 1-4

Have you tried moving the drive select jumper to different positions?

Of course this wouldn't explain "intermittent operation" - if the drive is jumpered wrong it shouldn't work at all - but who knows what Tandy did with the selects.

When the drive is completely disconnected, it does still say insert system disk. Is the drive select jumper on the actual drive? I moved a jumper on the board in the drive labeled “DS” and it didn’t change anything, accept the disk spun longer.

The junper I'm talking about is on the drive itself, normaly you will see something labeled 1-4 or possibly 0-3

On a typical PC, both drives have to be jumpered as 2 (or 1 if 0-3), and which of the wo possible drives it is is determined by its position on the cable.

Most other systems follow the original Shugart SA400 spec. (the first 5.25" drive) which supports up to 4 drives, and each drive is jumpered to reflect which of the 4 it is.

I have no idea which method Tandy used - Since we are talking about a PC, I would expect they followed the IBM method with the twisted cable (Does your cable have a twist - and are you certain it is the original cable)? - but it is Tandy, so who knows.

What can you tell with the drive LED: it should come on while stepping back to zero on BIOS entry, and should be on while the system is trying to boot from it.

Here's a simple test you can do, put the disk jumpers on the system board back to where they were originally, then try with the drive jumpered in each of the 4 select positions.

You should see the LED come on while stepping back, and for all but drive A: it should then stay OFF. If the drive is jumpered correctly as A: you should see in ON till the "insert system disk" message.