Computer wont post with RAM reinstalled

[Darflo]

I upgraded my computer the other week and ended up getting a new motherboard. I decided to put the old motherboard and CPU combo not to waste and build another PC. In that process I uninstalled the RAM from the motherboard and put it in my new PC while waiting for my new RAM to arrive. I just build the new pc and reinstalled the modules exactly like I had it before. Now the computer will not post. I will post if I have 2 of the modules in slot 1 and 2. But not all 4 will post. They are mix matched dims but they were working fine before. I down clocked the higher dims and still no luck. Any ideas?

[Darflo]

Haha well this is kinda embarrassing. I used Kryonaut liquid metal for thermal paste and somehow I got some right next to the pins on slot 3. I cleaned it and now it posts. Wow i'm a idiot.