I'm having strange experiences with floppy disk access on a Socket 7 motherboard. It's not that it can't access the floppy drive at all, but rather all floppy reads are corrupted and useless.

The hardware used:
The board is a Jamicon KM-V5-VPX with a Pentium 133 and 32 MB RAM. (https://theretroweb.com/motherboards/s/jamico … b-km-v5-v2-v1.0).
Connected to it are a Trident PCI video card, a Gotek with Flashfloppy, and a 512MB CF card with DOS 6.22 already installed.

What works:
BIOS detects CF card and will boot from DOS on the CF card.
Floppy drive will seek and activate. Gotek display shows it run through the tracks during POST as usual.

What does not work:
The system will not boot from floppy. It hangs immediately. Gotek shows a moment's search (track 0, heads 0/1) then stops with activity light on.
When booted from CF, DOS will read the floppy but shows errors and visual corruption in the directory listing. Will not launch programs. Sometimes, as a special treat, it shows "general failure reading drive A", but usually the corrupted patterns are very consistent between reboots, like the A:\ directory listing on a given disk having the same typos or garbage data every time.

What I have tried:
Using different known-good floppy images
Using the Gotek on other systems
Using a physical floppy with working disk
Replacing the floppy cable
Replacing the CPU
Replacing the RAM
Disabling onboard FDC and installing an ISA controller
Dumping BIOS to compare to Retroweb copy (no differences in binary)

At this point I don't even have a remaining theory of what might be causing the issue. Has anyone else experienced an issue like this?