of the three 4790k's he brought me I got what looks to be a pretty good one.
I got it delided and it still works but,.................... I have to get an EK neked kit.
Why you might ask, the stock bolts have shoulders on them that stop the bracket, without the heatsink the cpu is not pressed to the pins and there is no contact between the little cpu contact pads and the pins so you get a no boot/no post.