So if I understand it correctly you are now testing with a bare setup of only the A2000 mainboard and floppy drive with nothing else plugged in and it keeps asking for the system disk?
And even when you put the disk in, it still doesn't boot?
If so, can you see any read attempts, is the floppy drive light flashing? Or constantly on? Or no light activity at all on the floppy drive?
If you can't boot even after swapping the mainboard and power supply:
- something could be wrong with the floppy cable
it could be plugged incorrectly on either side
perhaps there is a loose connection in the flatcable
- floppy drive could be defective
If you have another drive to try I would suggest swapping the floppy. If that doesn't work you could try to swap the flatcable.
One time I also had some problems with my floppy cable. At one time during my testing the floppy kept running constantly and in the process erased part of my system floppy. So make sure you have a verified working boot disk during your testing.
