To whom it may concern:
Everyone, I also received the FPGA failure, when installing a new CF 6.1 SP1 into a HX controller. , I allowed it to continue rebooting, I pulled the power and tried again. Same result this time, after my third reboot I allowed it to "trying again Attempt #0 Thru Attempt #8 was the last I saw before leaving my desk for a minute, I returned and now the Display read "Failed to upgrade Replace mainbrd". I thought I had a bad PM board. Powered off system, removed PM board ch#10. Checked for U52 chip, as mentioned above. Reseated card, powered up sys and actually this time it came up online and now working fine.
Not sure how lucky I got but it worked !!!!