Question : HP Pavilion Slimline not powering on

I woke up this morning to find my computer not powered on, I always leave it running.
There was a green light that was light up in the back where the power supply is.
I unplugged it a few times and the light no longer comes on.

I contacted HP and I have to send the computer back to them.
Does this sound like a faulty power supply or possibly something else?

Answer : HP Pavilion Slimline not powering on

Either power supply or motherboard, possibly processor but not very likely.