Question PC turns on and mouse turns on, but not keyboard or screen?

[mx20100]

Hey guys,
My gf's pc is having troubles turning on and only fully turns on after the 3-4th try.
It gives the beep saying it is posting, mouse also turns on but keyboard and screen stay off. Her system is:
Core i5 4690k,
16gb of g-skill ripjaw RAM
GTX 970,
MSI B85M-E45 motherboard

What might the issue be?

 

[rgd1101]

make and model of the psu?

test with the gpu out and using only the igpu?

 

[mx20100]

make and model of the psu?

test with the gpu out and using only the igpu?

The PSU deluxe atx dlp-600w. probably doesn't have an 80plus certification.

She'll try, but she's asking how the gpu has anything to do with the keyboard not turning on.

 

[rgd1101]

the system is not working. try to figure out what the reason, could be psu or motherboard.