That boot floppy is the only 5.25" disk I have on hand so it's the only one I've used.
There must be something wrong with the floppy drive. It's a model YD-380 (with no brand name listed) 1.2MB drive made in "1986-44" (44th week of 1986?) and I genuinely don't know how to get to the heads or how to safely disconnect its extremely stuck Molex connector. I already broke a Molex connector off a 5.25 floppy drive once and I'd rather not do it again...
Hang on a second, you only have a single boot disk that does this, no other disks to try in the machine and no other machines to try that floppy disk in and you jump to "it must be the drive" Sorry to tell you this, but there is simply no way to draw that conclusion based on what you have told us thus far. Also, why jump to the hard thing (broken floppy) and not focus on the easy thing (bad boot disk)?
Get a known good boot disk and try that before taking the machine apart...
What sticks out to me is that you get the same corruption during the BIOS initialization of the VGA card (the purple bit that says something about Oak Technologies). That is a before anything is done with the floppy drive.
At this point we've got no real way to give you direction. It could be the floppy drive (you won't know until you try to boot from a know good boot disk), it could just be the disk (try that one in a known good machine, or try with a known good disk in that machine). But it could just as easily be the power supply running low when the floppy drive kicks in and starving the graphics card of power (try that card in a known good system, or try a known good display card in that system).
And for some future advice, if you seek help online, then a nice clear description of the problem with details on what you have or have not done will not only help you work it out faster, but will allow us to at least try to help you out.