If after changing the CMOS battery your computer won’t boot, this article will help you fix the problem. CMOS battery provides continuous power to the BIOS chip. BIOS chip stores all the BIOS settings ...

First, try turning on your computer by disconnecting all unnecessary devices. If this works, open the Device Manager after logging into your system and check the status of your graphics card driver.

This sounds like a power supply failure to me. I've had several pc's do the same thing. I think it is one of the most common failures as far as I know.