PC build troubles

[cal8]

Hi everyone,

I am new to PC building and since I got some parts for free I thought i give it a try.

 

The parts list:

 

MSI B450 A PRO MAX
AMD Ryzen 5600x
2 x 16GB DDR4 3200MHz Ram
Kingston 480GB SSD

 

Rather old:
GTX 460
HX 650W Corsair

 

Compatibility wise it should work except i missed something.

 

So i plugged everything in and gave it a try. All fans spinning lookin good i thought, so i plugged in monitor through hdmi (works with Laptop) but no signal no BIOS or stuff...
My first thought was that something is wrong with the graphics card so i checked that and the 460 need two 6 pins pcie power cables. For that I used a Y cable 6 pin from power supply to 2x6 pin. May that cause an issue?

Otherwise I am pretty lost
Is there some way to find out what components could make troubles? I see only the LED for the CPU on the motherboard is on. Should the others also light up?

 

Would love some tips on how to "debug" this

Hope i didn't miss any important info.

 

Best regards,

Alex

 

[GDRRiley]

==moved to troubleshooting==