ASUS Z170 Pro Gaming wont boot to screen, LEDs on + fans are spinning

Ergis1

Prominent
Mar 11, 2017
6
0
510
So I upgraded my motherboard, CPU and ram today and now it wont boot to screen and my GPU fans are not spinning whenever I'm starting the pc (my GPU is a GTX 970 STRIX 4gb) even when the LED that indicates that it has power is on. All LED's on the mobo are on and the CPU fan and the other case fans are spinning and working fine but nothing comes up on my screen. Ive tested to start my PC with 1 ram stick, taking out the GPU and putting in the screen cables into the mobo and it's still not working, tho I have a pretty old PSU which can be the case, but I'm not ready to buy a new one if it is the problem before I've got a confirmation from you professionals out there. The PSU is
Cooler Master M2 Silent Pro @ 720w

I went from this:
MB: ASUSTek P8Z77-V LX 1155
CPU: i5 2500k 3.30ghz
RAM: 8 gb 2x corsair vengeance 4gb ddr3
to
MB: ASUS Z170 Pro Gaming 1151
CPU: i5 7600K 3.8ghz skylake
RAM: 16 gb 2x corsair vengeance 8 gb ddr4 2133mhz
running a windows 7 64 bit OS
plz help
 

Ergis1

Prominent
Mar 11, 2017
6
0
510


My CPU that I have is 7th gen
and how would i be able to update the BIOS?
 

Ergis1

Prominent
Mar 11, 2017
6
0
510


The store I bought the mobo off is closed right now, so I can't check if i can return the mobo right now, but I'll probably just buy a new mobo, which one do you recommend I get?