I always try one last thing before I condem a motherboard.
One thing I would try before sending the board in, is try the board outside of the new case on a wood or cardboard box.
Not on the antistatic bag. Maybe something fell behind the board or something is shorted.
Also pull the battery and short the clear CMOS pins or push the button for 30 seconds.
Just one stick of memory , video card, monitor.  No other things attached but the PSU . Nothing at all in the USB ports.
If that works add a keyboard and mouse and see if you can get into the bios.
If it is still not working at that point it is the MB most likely, unless you have a CPU to try.

that can be true    I've seen where the cpu cooler improperly mounted can put stress on the socket   /warp the board  and cause issues as this ???    crooked tightening  /too tight    then they claim skylake got a thin lid  may bend in to something inside the chip cause a short  ?? [long shot I guess?]   heck MSI offers a guard
 
http://www.pcworld.com/article/3016421/hardware/msis-cpu-guard-aims-to-keep-your-skylake-chip-from-bending-under-pressure.html