And guess which signal that broken cable was?
/DSKCHG, the disk change detection line. What the switch I was talking about goes into.
But much easier to fix than the switch. Grats on that!
Nothing to add to this, but it surly took me back to the “good old” days of MS/DOS. I am amazed that so many of you are still playing around with it and with floppy drives, 5.25" ones at that.
Where in the world do you find all this hardware? And floppy disks, for that matter?
In 1981 I got a Commodore Vic-20, took it home and hooked it up to my TV and started. It had the OS on a ROM chip, so booted up insstantly. It used something very similar to DOS, so when that came out, had no problem writing programs in that. With the VIC, if I made a typo or incorrect entry, I got a message on the screen that read, “Incorrect Syntax.” It had no disk drive, but they came out with a small tape recorder that you could save stuff to, including data and programs I wrote. Later they called it the “floppy/stringy drive.”
Then they came out with a new computer, the Commodore 64, but I did not get that, but then they built the 128 which had the complete 64 in it for people who wanted to keep that. I bought that, and guess what, it had two 5.25" floppy drives. The top ones was for the program, the bottom to save stuff. Is that wonderful or what, all the huge memory those disks had. 
Commodore had a monthly magazine, and in it were always some very clever programs somebody wrote. Had to type them all in, which was a pain, but then somebody got a brilliant idea. Read the lines onto a tape recorder, then put on earphones and listen and type. Hit a foot switch to pause it. Finally I got a wonderful new thing, the dot-matrix printer
Anyway, when IBM came out with the 286, I built one. People were impressed, but it was pretty simple. Buy the case, the HDD, the memory chips, the power supply, etc and just fit it all together. No wires to solder. Back then it was much cheaper to do this than but an IBM, at least until the clones started coming out. Not so now.
I got a lot of DOS programs, and believe it or not, many still work on my current Dell computer. Still using WinXP and will continue until they pry it out of my cold dead hands. I am way too old (90) to go through the hassle of moving all my stuff to Win10, even with Laplink, if that still works. I started with the first version of Windows and upgraded to every one except Vista until now. I remember when every version was backwards compatible, so no big job upgrading.
Them was the days!
I did need to run DOS on bare metal this year to run a BIOS-update utility, but I haven’t needed to mess with MS-DOS ever since FreeDOS was released. It booted and ran just fine from a USB drive, no extra hardware required. Not that I don’t have 8" floppies, various widths of magnetic tape, maybe even punched cards, etc. lying around; if I suddenly needed to read one of those I would have a problem. There is too much hardware for a single person or organization to keep around and in working order, something to keep in mind even today.