Hello Swedge, Welcome to the ROG forum.
Here are a few things to try:
With your pc powered down, clear the cmos.
Try booting with one stick of ram.
If that doesn't get you going, remove your cpu cooler/waterblock and cpu from the socket. Inspect the cpu socket with a magnifying glass for any bent or misaligned pins. If there are any bent pins you can straighten them with a small thin bladed pocket knife. You must have good eyes, a steady hand and do it carefully.
Sometimes uneven pressure from the cpu cooler can cause code 55 so when remounting your cpu cooler/waterblock, make it just snug and be sure to put even tension on all four screws.
Did this help at all?