Is my Motherboard dead?

[HoldTheCone]

So i have had my custom built computer for about 3 years and recently the computer will crash. Often however turning on the computer is a mission even if it doesnt crash. After only several attempts will the computer boot. At first i believed it to be either the motherboard, GPU, or power supply. I quickly ruled out GPU because the fan turns and graphics are fine whenever it does work. Now the question is is it the power supply or the motherboard that is defective or if any. All fans spin and lights come on. It seems everything is recieving power except the motherboard. There is a green light in the back of the motherboard but it doesnt turn on. When it does the computer boots. I checked the power supply cables and they both seem snug into the motherboard. This is making me highly believe it is a dead motherboard. Could this be the case?

 

[popatim]

Sounds like a power supply problem to me. Do you know what the green light is for or trying to tell you?

 

[HoldTheCone]

Sounds like a power supply problem to me. Do you know what the green light is for or trying to tell you?

i'm pretty sure its just a green light for the connections on the back. (example: ethernet slot, audio slot, usb slot.) I noticed it and realized the motherboard wasn't getting power or neglecting it. This is what drove me to post on here because it's quite difficult to judge which it is, a PSU or motherboard problem.