Question PC freeze & no signal ?

[Verty121]

PC specs:

i7 4820k (no oc)
16gb 1600mhz ram
GTX 980 Ti
118gb SSD
1tb HDD
700w PSU

The problem is that the monitor randomly displays no signal while everything else is on. Then i have to restart the pc. this happens often.
i have bought a new cmos battery and switched to a new PSU and the problem is still here. i have checked the ram with memtest was fine. I have never overclocked the cpu or gpu or ram.

EDIT: CPU temps never go past 60c even in long sessions of gaming, gpu temps on max load after a while stay at 68c

 

[rgd1101]

brand and model of the psu?

 

[Verty121]

silverpower 750w bronze psu i have tried with as expensice corsair supply and the problem still happened.