Just a thought here. When you open the case to the IC-402 look for a jumper near the system battery and CMOS ROM chip and see if there is a way to reset the unit (usually it will say 'RST' next to it). I have done this on quite a few controllers from EFI and some Toshiba stuff i.e. GL-10x0 and I have had fantastic results. After you try this if it still does not work pull the memory out of the Fiery and run a memory test on it. You will need to install the memory in a compatible device with a CDROM boot capability. Use Memtest86, you can get it here:
Memtest86.com - Memory Diagnostic. If there is a ton of errors replace the memory.