When your computer wont boot and you've done process of elimination confirming that the RAM is the culprit, mostly you might think of replacing the RAM. Before you throw away your RAM, you might want to try this troubleshooting first in this article. There is also the possibility that your motherboard's RAM socket is already loose, specially if it is already old. The motherboard's RAM socket contact pins might not all touching the RAM's golden finger. Disclaimer: webfoobar assumes no responsibility for any data loss or permanent damage executing the following tutorial steps (use at your own risk).
Mostly, when we insert our RAM into our motherboard, we insert it firmly. My troubleshooting suggestion is try inserting the RAM slightly loose (not inserting the RAM all the way down the bottom of the socket), in the figure below shows at the left the RAM is firmly inserted and at the right the RAM is inserted slightly loose:
… and boot your computer. If it still not booting, try removing the RAM and re-insert it more slightly loose (this is a trial and error).