Has anyone used this motherboard with 64GB memory?

I'm running two 32GB kits from G.Skill (F4-2133C15Q-32GRR) with a 5930k and now seemingly have two dead boards. The first ran for almost a week, powered off for the weekend and then failed to post or even power up on Monday. Replaced all parts other than the board with new parts and had the same result.

Finally gave up on the initial board and moved everything over to a brand new Extreme4 and it lasted only a day, however this dead board at least powered up but never posts.

I've tried different power supplies (600W Silverstone & 650W Corsair), another processor (5820k) and 16GB (G.Skill) set of ram without any success. I've reverted back to old hardware and all seems well. Any ideas?