I've managed to start my PC. Sorry for the late reply.
Processor Intel(R) Core(TM) i5-4460 CPU @ 3.20GHz 3.20 GHz
Installed RAM 20,0 GB (Gskill and Kingston)
MSI PC MATE Z97 DDR3 MB
SAMSUNG 860 EVO 500GB SSD
KINGSTON 128GB SSD (has W10 installed)
NVIDIA GeForce GTX 970 MSI GTX 970 4G
650w Everest PSU (had it with the case)
So far, no problems occurred. I've tested the computer by running games on ultra settings to check whether It's PSU related problem or not.
For some reason, DP cable couldn't receive the signal, I had to use HDMI in order to get signal to the monitor. It worked, then I switched back to DP.
My brother told me that he had downloaded a pirated game. I've checked the website and thought It had malware, since It's a website that contains pirated games. I already had suspects about my computer, somethings weren't right like stuttering browser and youtube videos, short freezes and choppy audio like something is forcing the CPU and causing all kinds of problems. Anyways, I've reinstalled Windows 10 by purging the disk C. These issues are gone, never happened again.
But still, I wonder is it going to happen again or not. I don't want it cause more problem If it's PSU related or other components.