Computer wont display on monitor

So I decided to put new thermal compound on my CPU, so I took the old completely off, re-seated the CPU put the heat sync back non etc, now when I turn on my computer all fans run at max and don't idle even after five minutes and there is no display to my monitor from either onboard or the graphics card. I've tried a different computer with the monitor and VGA cable and they work and I've also checked if the CPU was seated correctly with no bent pins. I'm all out of options, does anyone on here have any suggestions

Also after trying again there is a series of 4 beeps and it keeps on repeating, also there is no power to the mouse and keyboard