Have I fried my first build? =/

[BearTrapGazelle]

Hey guys, was looking for a little advice.
I've recently finished my first build and I was over the moon with its performance.
Worked for 2days then while playing a game last night ('Smite' not a particularly high end game) the pc crashed and now wont turn on.
There is still power going to the mobo as the lights are on but nothing is happening this morning.

My instincts are either the PSU isn't powerful enough and it's overheated or possibly the CPU has overheated.
I don't have a spare PSU to try out.

Any advice?

Build is as follows:

AMD Bulldozer 8150 (stock cooler)
Asus Sabretooth 990fx mobo
Radeon HD Sapphire 6680
16gb corsair 1333 ram
64gb crucial ssd
2TB Seagate HDD
500W PSU (came with cheap case as I was coming to the end of my budget)

 

[gussrtk]

when you press the power button does everything at least go on just for a split second?

take out the main motherboard plug and plug it back in after 15 seconds see if something happens. try turn it on.