Yeah, the mpc2000xl does not have a fs1, but I believe the mpc2000 does- the 2000xl has an fs80 it's green on mine and it's a rectifier and has a label on it 1x1.
Check the circuit diagrams and follow from the 25 pin (fifty actual pins) SCSI input.
I have a problem loading from a disk and came across this thread and now I wonder does anyone ever get to fix this problem? Is it a software issue?