moving parts from pre-built to new case

Hi, recently I ordered parts to transfer hardware from a pre-built Dell XPS 8940 so that I could improve cooling and generally upgrade the device. Assembling everything seemed to go smoothly, and I was able to get the computer set up fairly quick. Everything seemed fine until I ran into an issue...

Right, so I have an omen 880 and I have done a couple upgrades over the two years I had it. I wanted to upgrade the case so I chose a Corsair 280x and began moving it in. Just before moving it I used it and it was all working fine. After moving it it now no longer shows any kind of life, no fan...

So I have an HP Omen 870-244, and I've noticed that the cooling on it is terrible. I've wanted to take all the parts from the Omen, and move them into a new Case. I was looking at an "NZXT H210", but am not sure if everything would work out. Here are the specs of the current PC: Core I7-7700...