The IIfx doesn't seem to want to boot properly now. I get the chime but nothing else. It doesn't attempt to access the hard drive or the disk drive (it did the first time I turned it on). I unplugged everything except the video card and disk drive, but still nothing. Any ideas? I made sure all the memory and the ROM board were seated properly and all the cables were plugged in.
Tempest
Try unplugging the SCSI cable from the logic board and see if it accesses the floppy. Sometimes a misconfigured SCSI chain will hang the machine during configuration.
Are two of your banks of RAM filled, or one? If two, you might try removing the memory in bank B. If that doesn't help, pull Bank A, and install the SIMMs you took from Bank B in Bank A.
Oh, if you have only one bank of RAM filled, did you perhaps move the memory to the other bank? Again, the memory is fuzzy, but I think that Bank A must be filled if only one bank is being used.
Ah, here we go:
http://developer.apple.com/legacy/mac/library/technotes/hw/hw_25.html
larger SIMMs must go in Bank A, the bank closer to the rear of the machine.