Question Do i need 8+4pins to the CPU?

[Fameroun]

I've read that it isnt necessary to connect the 4 pin to the CPU power on the mobo as long as I have the 8 pin connected.
But since my new MSI MPG Z390 GAMING PRO CARBON and i5 9600k won't post anything on the screen im wondering if I have to have both 8pin and 4pin connected to the "CPU_PWR" to make it work?
I've tried almost anything but THAT so is there a chance that this mobo or CPU needs both?

 

[Rogue Leader]

Update:
The Mobo is broken but the CPU is fine. Bought a much cheaper mobo and placed the CPU in it and it works great. The service men that checked my mobo and CPU said that the power grid was -------- up and probably from me but they also found a bent pin in the USBC1 port so there already was a fault in the motherboard. Will try to get it on warranty and shouldnt be impossible since i dont even have a connector that fits that port.
We learn when we make mistakes.
Thanks anyways for the help.

Glad that worked out, you got tremendously lucky.

 

[Darkbreeze]

So, like I said from the VERY beginning, it was the motherboard. I'm glad you got it sorted out.

 

[NightHawkRMX]

Good to here. Just be carefull nextime.