POWER9 Blackbird Powerup Issue

I’m have an issue with my blackbird and can’t get support from RaptorCS
because it’s out of warranty.  So I wanted to see if anyone else has
experienced the same or similar issue.

The blackbird refuses to boot into OpenBMC after being powered off to
install a discrete GPU.  The OpenBMC led ( ) continues to flash rapidly
with a momentary pause, then continues to flash rapidly.  The power led
stays orange.

I’ve checked raptors wiki, forums and the how-to guides, but don’t see
anything similar to my issue. I’ve tried leaving it completely powered off
for several days but the problem still remains.

Any suggestions/help would really be appreciated.

Regards