I went to shut down my computer and I got a grey screen and it wouldn't shut down. I held power button and tried turning it back on and I got 3 yellow lights. I tried removing cmos, draining power and putting back in original ram so I could pull up the screen to say ram has changed. I get three yellow lights in slots 2/4 but no yellow lights in 1/3 in the memory slots. I can't get anything to come up on screen DP or HDMI. Please help.