I just installed a new AMD 1090T on a ASUS M3A78 EM motherboard and now my PC is not starting up. I checked and ensured that all plugs and connectors are connected to my motherboard. I plugged in the PSU cable, and hit the power switch. My motherboard's LED light comes on. I then press the power button - and nothing. No POST, no beeps, and no fans spin. Only the motherboard light comes on. This is what I did: I updated the BIOS prior and the latest BIOS support the 1090T CPU. I've used this PC fine for a month or so with these BIOS. I turned off my PC, turned off the power and unplugged it. After waiting for a few minutes, I opened it up and unplugged all plugs, video card, PCI cards ect. I then removed my motherboard. Next I removed a Sunbeam Core Contact 120mm heat sink/fan - this took a bit of effort, had to physically remove motherboard before getting it off. I then removed my 9950BE and installed my new 1090T and 92mm Xigmatek LOKI heatsink/fan with TX2 thermal compound on my ASUS M3A78 EM. I am concerned the motherboard might have got damaged during the process of removing and installing my CPU heatsink. But the light on the motherboard comes on when I plug in the power, does that mean it is not a motherboard-related issue?