There are a couple of very easy steps that would allow you to troubleshoot a motherboard that doesn’t power up but be sure to get a grounding wrist strap to dissipate any static electricity that would kill any electronics you may touch. Make sure all power connections are unplugged before servicing a computer to prevent stray electricity from kicking you with a jolt of electricity. As with many PC problems, it would be best to strip down the PC to a bare-bone system, which would be the, Power Supply, Motherboard, processor, memory, hard drive and the necessary CPU fan. Take out all peripherals that may be connected to the computer and un-hook all connected printers and other devices. This would allow you to do an elimination process whereby you get to add components that may be causing the failure to power up.