I've been reading this review and something caught my attention. According to the article...
"hen we started testing for this review, the main instructions we were given was that when changing between Skylake-X and Kaby Lake-X processors, be sure to remove AC power and hold the reset BIOS button for 30 seconds. This comes down to an issue with supporting both sets of CPUs at once: Skylake-X features... See More
some form of integrated voltage regulator (somewhat like the FIVR on Broadwell), whereas Kaby Lake-X is more motherboard controlled. As a result, some of the voltages going in to the CPU, if configured incorrectly, can cause damage. This is where I say I broke a CPU: our Kaby Lake-X Core i7 died on the test bed. We are told that in the future there should be a way to switch between the two without having this issue, but there are some other issues as well."
I find this troubling. I hope it gets fixed right away. Looks like motherboard makers have a lot of things to do.