Question Computer Freeze - Black Screen when I boot up

[Mikadinho]

Hello everyone,
This is my first post here and I come for your help concerning some PC issues that I had for a while.
Basically, my computer randomly freezes. I thought it was only while playing video games but now it can happen no matter what I'm doing.
That's one thing, but the other one is I often have to boot/reboot my computer several time before I can have the normal screens showing up. I usually get black screen with the monitor saying "No Signal".
I thought it was the monitor (i have two) but i tried one without the other and i have the same problems. I tried to remove all the external usb drive (such as mouth, keyboard etc.) but it doesn't work either. My CPU temperature are cool.
All the drivers are up to date.
And, after a while of booting up and freezes, the computer works just fine and i have no problem until i turn it down and i boot up the next day.
So, i have no idea what causes the problems and how to fix it.

PC Specs:
Processor: Intel Core i5-6600K CPU @3.50 Ghz
Memory: 8 GB Ram DDR4
Graphic Card : NVIDIA GeForce GTX 1070
Windows 10 64 bit

If you need any additional information, i'll be glad to give them, thanks in advance.

 

[Lutfij]

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. List them like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS: include version of OS.

Also include the age of the PSU. We can move forward from there.

 

[Mikadinho]

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. List them like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS: include version of OS.

Also include the age of the PSU. We can move forward from there.

First of all thanks for the quick answer and then sorry for the that i didn't included the full specs. So:

CPU: Intel Core i5-6600K CPU @ 3.5GHz
Motherboard: ASRock Z170 Pro4S
Ram: DDR4 Ballistix Sport, 2 x 4 Go, 2400 MHz, CAS 16
SSD/HDD:

• HDD Seagate Barracuda, 2 To
• SSD Kingston SSDNow UV400, 120 Go, SATA III

GPU: Geforce GTX 1070
PSU: Corsair VS550, 550W
Chassis: Aerocool CS-1101, Black
OS: Windows 10 Professional Version 1903