Intro: I recently came across an issue when building my current PC, which I could not get the PC to POST. I had matched dual channel RAM in the correct slots and PC would simply not POST with the DRAM light lit on my motherboard. Tested with 1 stick of RAM and the PC would POST. So, if this is you and you are scratching your head, then I may be able to help some poor lost soul.
Long story short, the issue I had diagnosed and solved was too much CPU pressure caused by the CPU heatsink. Now, I know this has been somewhat covered through answers, but I never really came across an organized post regarding it.
So, what has caused this issue and why? What caused it was simply apply too much torque to the screws on the heatsink backplate along with too much torque on the screws securing the heatsink to the CPU itself. The heatsink I had was a Noctua NH-D9L. This particular heatsink has thumbscrews for the backplate to the motherboard and spring loaded screws for the heatsink to CPU. With any PC build....take your time and REMEMBER, go finger tight, then a 1/4 turn, or slightly snug, then 1/4 turn. Thats it! LASTLY, apply even torque as you go to ALL the screws. Don't torque one screw by itself all the way, then move on to the next....do it evenly. Do not overthink it, or feel like, "surely this isn't tight enough!"....well it is. Unless you notice obvious wobble, do another 1/4 turn. If no wobble....just stop.
With too much pressure, it causes the CPU to sit funny, or make poor contact. Remember the memory controller is apart of the CPU. Also, it may have caused the motherboard to flex.
Other Potential Issues: Another issue that may have happened due to Hulking the screws, is you bent a CPU/Motherboard pin. Obviously, you would have to remove the CPU and take a look at it as best as you can. I looked at mine and honestly, I don't know if I would have been able to spot one unless it really jumped out at me. I have read that a bent pin is tough to do (unless it was simply a hardware deficiency), therefore not likely to have occurred.
Anyways, I was pulling my hair out trying to figure out how a brand new MB, CPU, and RAM could not POST. Hope this helps someone.
Long story short, the issue I had diagnosed and solved was too much CPU pressure caused by the CPU heatsink. Now, I know this has been somewhat covered through answers, but I never really came across an organized post regarding it.
So, what has caused this issue and why? What caused it was simply apply too much torque to the screws on the heatsink backplate along with too much torque on the screws securing the heatsink to the CPU itself. The heatsink I had was a Noctua NH-D9L. This particular heatsink has thumbscrews for the backplate to the motherboard and spring loaded screws for the heatsink to CPU. With any PC build....take your time and REMEMBER, go finger tight, then a 1/4 turn, or slightly snug, then 1/4 turn. Thats it! LASTLY, apply even torque as you go to ALL the screws. Don't torque one screw by itself all the way, then move on to the next....do it evenly. Do not overthink it, or feel like, "surely this isn't tight enough!"....well it is. Unless you notice obvious wobble, do another 1/4 turn. If no wobble....just stop.
With too much pressure, it causes the CPU to sit funny, or make poor contact. Remember the memory controller is apart of the CPU. Also, it may have caused the motherboard to flex.
Other Potential Issues: Another issue that may have happened due to Hulking the screws, is you bent a CPU/Motherboard pin. Obviously, you would have to remove the CPU and take a look at it as best as you can. I looked at mine and honestly, I don't know if I would have been able to spot one unless it really jumped out at me. I have read that a bent pin is tough to do (unless it was simply a hardware deficiency), therefore not likely to have occurred.
Anyways, I was pulling my hair out trying to figure out how a brand new MB, CPU, and RAM could not POST. Hope this helps someone.