When in doubt , use Post. Plug in a speaker on the motherboard.
"Check the POST. POST stands for "Power On Self Test". This is part of a computer's startup program that is used to diagnose the keyboard, random access memory (RAM), disk drives and other hardware to make sure they are working properly. If the POST detects any errors in the hardware, it will either display a text error message on the screen or a series of short and long beeps. "
You can find videos on how to post your Pc and understand the beeps. This is how I figured out I had a bad ram stick and messed up mother board. If you have an extra computer or a friends. Try using the Ram sticks in a different Pc if nothing else works.
hope this helped.