PC randomly(kinda) shuts down but stays powered on!

[DartVather]

So my pc lately has been shutting down by itself but it stays powered on, this happened like 7 or 8 times when playing games like GTA V or RUST, the last time it shutdown(always stayed powered up) i wasn't doing anything that requires a lot of "power" from the pc, i was just browsing the web.

Between all the times it shutdown i got this message ONCE: Message.

When the PC shuts down, i ear all the fans "reset" like when you turn the pc on, black screen and the power buttons don't work, i press them and nothing happens, if i want to make it work again i need to turn the button on the PSU off and wait a while(if i dont wait it turns on but i can't do anything, black screen).

Pc specs:

MotherBoard: Asus M5A87 (AMD 770/870 (RX780) + SB810/SB850)
CPU: AMD Phenom II X6 1100T Black Edition 3.3GHz Thuban
GPU: Sapphire Radeon HD 6970 2GB GDDR5
Ram: 16gb
PSU: ATX 600W LC-POWER LC6600GP2 V2.3 14cm [bk]
Link to GPU

I searched a lot online and i suspect its the PSU but it could also be the motherboard. If it is the PSU im thinking in buying the EVGA SuperNOVA 650 G2 and then upgrade my GPU to MSI R9 390/390x, tell me what you guys think.

Maybe some useful information:

For some time now that i have been hearing this noise from the PSU, it looks like theres a bee inside, usually it lasts 2 minutes then goes away.

The pc is NOT overheating.

I do not have another PSU to test.

I bought this pc(new) in September 2011.

 

[IHaveALaptopAndItsShitty]

Bee? Thats very unusual.

You should get that bee out of there, Its not safe to keep it in there.

You should also consider upgrading that psu.

 

[tiny voices]

Your PSU is trash. Replace it ASAP before it fries the PC.

You need a quality unit. Antec, XFX, seasonic, EVGA (G2,B2,GS)

 

[DartVather]

Bee? Thats very unusual.

You should get that bee out of there, Its not safe to keep it in there.

You should also considering upgrading.

I mean i ear that BZZZZ noise you ear when you are near a electrical plant.

Bee? Thats very unusual.

You should get that bee out of there, Its not safe to keep it in there.

You should also considering upgrading.

The PSU is trash i agree on that but do you think the problem is from the PSU?

 

[tiny voices]

Yes the problem is the PSU.

If the problem is the motherboard it is DUE TO being damaged by the crap PSU.