Blank Monitor, keyboard and mouse gets power.

My CPU turns on and keyboard and mouse are receiving power too but the monitor remains blank. My computer all of a sudden decided to freeze up, and upon restart, the monitor won't get a signal, the light stays yellow. All the other components appear to be running fine, all fans spin. I've tried two monitors on it and I've unplugged and rearranged the RAM, and still nothing. Everything is plugged in well. So, I don't think that can be the problem. I've tried clearing CMOS, but it still didn't work. How do I fix this?