unexpected shutdowns while playing

[Zeimarr]

Hey.
Im having trouble with my pc doing unexpected lags and shutdowns, usually while playing games this occurs.

My gpu is a pretty new gtx 770. Rest of pc is like 3-4 years.

I also notice when i get the shutdowns, the DRam leds lighting up on the motherboard.

Any clues on this?

 

[wsstunt]

anything over heating?

 

[ko888]

What's the brand and model of the system's power supply unit?