No signal to monitor after reseating RAM

A couple weeks ago, i was cleaning my desktop computer, and for curiosity, i took out one of my 3 ram chips and put it back in. After that, when i tried to boot my computer it made ticking sounds from the motherboard, and the cd drive kept making jerky moves and sounds and there was no signal to monitor. I turned it off, turned it back on, it worked like normal. I turned it off again and turned it on, it worked. The computer works fine when it works, and when i reboot it right after i turn it off, it works fine as well, but when i turn it off overnight, the next morning it wont boot and make the same ticking noise with no signal to monitor. I have to keep turning on and off the computer until i get lucky and it will boot.
I tried:
-clearing CMOS with jumpers
-reseating all my ram, tried booting without any ram
-took out the power cord, held power button, reconnected
None of these worked

Please help!