treeman wrote on 2020-11-16, 04:30:

I have a V2 and I damaged it years ago trying to desolder the rtc. Right in the same area and qfc chip. The Floppy never worked […]
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I have a V2 and I damaged it years ago trying to desolder the rtc. Right in the same area and qfc chip.
The Floppy never worked and I never pieced it that its from the damage in that area. I never really looked far into it since all my floppy disks are now unreadable and the only thing the floppy is good for the the boot up sound.

However if it helps you can confirm similar damage and fdc error.

This is my exact error when enabling floppy in bios

Same Error with mine

Eep386 wrote on 2020-11-16, 17:16:

CB18? It kind of looks like that component is an SMT ferrite bead. They look identical to SMT capacitors but aren't.
Of course I'm not saying that I am entirely sure that is what CB18 is.

Also, try checking the clock inputs for the UMC I/O chip. If both the COM and floppy ports are dead, that would cast some suspicion on the clock signal that drives both. I wish I could GET datasheets for UMC parts though, or else I'd tell you what pins to check!

Feipoa said it measured the CB18 component to be a 100nF capacitor. Can anyone actually desolder it and check what this thing is ?

How to check the clock inputs if I do not have a datasheet ? Should I trace a clock signal from something known ?

I wish I could help you here further, but without a datasheet it will be difficult to say where to trace the signal.
You can try tracing from something known.