I ordered a new formatter (just got here today), swapped the components, and had the exact same issue with the new formatter. The new formatter came with a 256 MB memory module (copy memory, I think), so I decided to try swapping the memory modules out one-by-one.
Turns out one of the memory modules is bad.
I wanted to check the original formatter, so put the known working components on the original formatter, and it works just fine.
So a $300+ part to find out a $35 part was bad. At least I have a spare formatter now, and know what to look for in the future for this particular light code.
Mike