Hi
Concerning your first problem, the issue is the i7-4790K, just to be clear the CPU it self is not bad,.. Intel decided to thew us loyal customers under the bus on the haswell refresh by deliberately not releasing a BIOS that supports the haswell refresh, when asked about it they say its coz they are no longer in the business of producing desktop boards, so sorry buddy unless Intel changes their mind which is unlikely, you will have to purchase/exchange your CPU for any other 4th CPU before the refresh, check compatible CPU list for the board. I am ****** off too about this fiasco.
Second problem is what I'm curious with coz i have just checked my PC and to my surprise that video LED is off, should it be like this INTEL answer!!!!???