Thanks for the help guys, same story though. Tried different vccio and vtt voltages, booting with the 2400 multi then trying to go to 2600 straight after, manually setting loose tertiaries, leaving tertiaries on auto, using the PSC profiles. Nothing seems to work, the board doesn't even seem to be trying to boot, just instant 55 error code. I'll try flashing the bios again and seeing if that helps, but I'm not too hopeful at this point. Tried multiple PSC kits that are all able to do 2600 on my MVF.