Applied new thermal paste and now my computer automatically shuts off

[Pongsona]

Please help because I'm honestly freaking out right now.

I applied new thermal paste (hyper 212 evo) and now my computer WILL start but it shuts off within seconds, then turns back on and shuts off again.

I didn't had to remove the motherboard so I know everything is connected. I switched the cooler master fan that came with the heatsink because it was broken but it worked just fine before I applied the thermal paste. The new fan I got is Noctua NF F-12.

Any idea what may cause this problem? Please help. ):

 

[carnageX]

How much thermal paste did you apply? Did you remember to clean the old stuff off first? Is your heatsink properly secured down?

Double check all power connections and components (e.g. RAM and PCI cards).

May also be a good idea to unplug all extra components other than 1 stick of RAM and (if you don't have an onboard GPU), your GPU.

If it still doesn't boot, you can try removing your motherboard from your case, hooking up basic components again, lay the motherboard on a piece of cardboard and try to boot up outside of the case in case something on the mobo is shorting out.

 

[Pongsona]

This was my first time reapplying thermal paste so I'm no sure if I applied too much. I need to purchase new thermal paste so I can't do any testing until I do.

And yes. I did clean the old stuff first. I had to remove the Kingston HyperX ram because I needed more space to screw the heatsink. I'm not sure if that had anything do with it. I'm pretty sure I plugged them back in correctly.

 

[carnageX]

You only need to apply a rice-sized dot of paste in the center of the CPU, and then just put the cooler on. The weight of the cooler + pressure from securing it down should spread it out evenly.

Make sure the RAM is fully inserted and clipped down with the side-clips since you had to remove them.