This was my first time building a computer. I got all the parts for it minus the graphics card. I installed everything and started it up. The speaker beeped then it shut off, then started back up. I turned off the power then started it back up it did it again. I checked my ram cards they weren't in all the way so I fixed that. It ran for a while but the screen wouldn't display. So I turned it off tried tinkering(unplug and replug) When I did this I took off the CPU fan by mistake removed the thermal paste and ended up starting the computer again without the paste it restarted itself again. I turned it off. I waited a while and had a friend come over and said you shouldn't have taken the thermal paste off. I got more thermal paste and reapplied it. Tried it again the speaker is no longer beeping but it restarts still. We unplugged the CPU power it runs and won't restart. I plugged the power back into it it ran but no video display. Little while later it started restarting. I took out the power to the CPU once again and no restart problems. Did I fry the CPU or is it a motherboard issue?