Question I'm at my wits' end... Please help before I toss $1k worth of gear. (MSI PSU)

[slapawrapa]

Brand new MPG A750F for new PC build.

It clicks and flickers the mobo on and off instead of supplying steady power. MSI B550M PRO-VHD.

Connected via just 24 pin- clicks. Connected by 24 pin and cpu - clicks. Connected by 24 pin on mobo and psu, and cpu cable (which splits off from 24 pin cable) going only to the psu - clicks (this somehow worked with the same psu on my last board).

What am I doing wrong? I'm hating getting back into PC building, it was so much simpler when I first started out (aeons ago).

Please help me.

 

[--SID--]

and cpu cable (which splits off from 24 pin cable)

It splits from what???

 

[slapawrapa]

It splits from what???

 

[slapawrapa]

Never mind, I'm an idiot. I was connecting the smaller one to cpu on the power supply instead of "motherboard".

 

[Eximo]

View: https://www.youtube.com/watch?v=BPknZ3Lk4xU