So my daughters computer stopped working randomly ...

[qwikjax]

She has this motherboard https://www.asus.com/Motherboards/P8Z68V_PROGEN3/

I thought at first it was the power supply because it just shut off, I unplugged it and used wire to connect the green wire with the adjacent black wire and the fan spins (that means it is still good right?) which leads me to believe it's the motherboard?

Everything was built about 7 years ago I would guess, and nothing has been replaced.

It's an antec 650 watt cpu if that's needed.

I'm just not entirely sure how to be positive what the problem is, and then once I figure out the problem if it is the motherboard that one isn't sold anymore so I don't really know which motherboard to buy to be compatible with the current motherboard (not that it would need to be compatible with the current motherboard, but this would ensure it works with the cpu / gpu and things she currently has)

The red cpu led light is on when I turn on the mobo, so if it's the cpu it had to have just went bad as its been installed for years, or could it still possibly be the motherboard?

 

[Eximo]

She has this motherboard https://www.asus.com/Motherboards/P8Z68V_PROGEN3/

I thought at first it was the power supply because it just shut off, I unplugged it and used wire to connect the green wire with the adjacent black wire and the fan spins (that means it is still good right?) which leads me to believe it's the motherboard?

Everything was built about 7 years ago I would guess, and nothing has been replaced.

It's an antec 650 watt cpu if that's needed.

I'm just not entirely sure how to be positive what the problem is, and then once I figure out the problem if it is the motherboard that one isn't sold anymore so I don't really know which motherboard to buy to be compatible with the current motherboard (not that it would need to be compatible with the current motherboard, but this would ensure it works with the cpu / gpu and things she currently has)

The red cpu led light is on when I turn on the mobo, so if it's the cpu it had to have just went bad as its been installed for years, or could it still possibly be the motherboard?

That isn't a conclusive test of the power supply. That just proves that power is available on the 12V rail(assuming the fans stayed spinning, if they stopped immediately it proves nothing), but it doesn't mean that is 12V.

Power supply outputs primarily 12V, 5V, and 3.3 volts. The 12V rail can still output a voltage high enough to spin a fan but not enough to operate the VRMs that run the CPU. The motherboard logic typically takes in 5V to operate the BIOS, so if that is dead then it won't know there is a CPU.

If you have a multi-meter handy, you should disconnect the power supply from the computer. Use the same method to turn it on as before, and measure the Yellow (12V) to ground and the Red (5V) to ground. You can check the other voltages, but these are the important ones.

Next step would be to unplug everything that isn't essential to operation. Basically you just need CPU, Memory, and the power supply for a very basic test. If the CPU has onboard video give that a try, if not you will need a video card to see any results. This is to rule out a short circuit caused by another component.

If all that pans out, motherboard would be the next logical thing.

Z68 means LGA1155. That covers the following chipsets (H61, H67, B65, B75, H71, H77, Z68, Z77, Q77, Q67, P67) Intel went a little overboard with LGA1155...

Your board is ATX, so any board ATX, Micro ATX, or Mini ITX will work.

If you have an opportunity to take the CPU to a computer shop they may be able to test it for you before you spend any money.

A new motherboard, CPU, and memory isn't all that daunting right now. i3-8100 is a quad core and is a fine replacement for any second gen CPU. Also some decent enough Pentiums. AMD Ryzen quad cores are also quite inexpensive.