A while back I bought a new computer. The motherboard I bought was an ASUS P7H55-M PRO/USB3 and I have an i3-550 with 4gb of XMS3 Classic Ram (2 x 2gb sticks, 1600mhz). When I bought the computer I set it up with the stock intel cooler and put the two sticks in dual channel slots which worked a treat. After I tried overclocking my CPU was gettin really hot and I decided to fork out for CM 212+ Hyper cooler. When I installed the cooler I noticed that my computer wouldn't boot and eventually found RAM was the problem. When I put the two sticks in single channel, next to each other, the computer booted fine.
Fast forward a year and I bought another 4gb to go along with my GTX 670 to give my gaming a little extra oomph. The RAM is the same brand and timings but when I put the four sticks in I have the same problem as I have when I put two in dual channel, which is no boot.
If it's important, my PSU is an OCZ ModXStream 600w modular. Please help me, this is doing my head in!!!
A ram stick may not be seated, or one is bad; test each one at a time with memtest. The problem started with the hyper 212, so you may want to reinstall it. Sometimes too much force is exerted around the socket area with any cooler; don't know if this effected the ram; you'll just have to test them. I use an esd strap when handling components several times; use one if you have it.
I tested all the sticks already and they all work. The problem seems to be two of the ports but i was just wondering whether anybody knew why they suddenly stopped working or at least had an idea. I'll try re-seating the cooler. I'll update with my progress.