8 pin cpu connector doesnt match motherboard

Solution
You're right, the shaped plastic pins on the plug from the power supply don't match the motherboard socket exactly. However it is keyed in such a way that it can fit. On the pic of your motherboard in your first post, there's a pattern of square and rounded square holes. The square pins rounded on one side will fit in a square opening if needed, but the placement of square pins and square holes in the socket will ensure it only matches up one way.

Yes, the plugs can be a bear even on older equipment since they typically get plugged in once from the start and aren't touched again. Sometimes the plastic molding is just slightly off in size and requires a lot of force (but you don't want that plug loose at all or you'll have a loose...
That looks like the right connector. The way you had it in your hand, if your hand was at the top of the motherboard - bend your hand so your thumb is at the top of the motherboard and your fingers are near the blue heatsink. Look at the angle of the connectors, it will only fit one way.

Assuming the top of the motherboard as it sits in the case is the 'top' (cpu above, pci slots below) then the angles on those funny non square shaped plugs face 'down' and there's 2 fully square pins that are offset/diagonal from one another. You might have to wiggle it to get it to fit, but it looks like it should go.
 

[strike]This is my first pc build so i need to ask if they shape of the black part matters? like square vs rounded.[/strike]nevermind, it does. my plug definitely does not have 4 square and 4 rounded like the motherboard does.
Ive been trying to get these to "snap" in properly but im afraid ill break my board.
 
ahh yes yes. you're right. Apparently rounded pins can fit into square spots. so it should be fine. I will try again 🙁 and yea i have been supporting it. maybe i will split it and try each half first
 
You're right, the shaped plastic pins on the plug from the power supply don't match the motherboard socket exactly. However it is keyed in such a way that it can fit. On the pic of your motherboard in your first post, there's a pattern of square and rounded square holes. The square pins rounded on one side will fit in a square opening if needed, but the placement of square pins and square holes in the socket will ensure it only matches up one way.

Yes, the plugs can be a bear even on older equipment since they typically get plugged in once from the start and aren't touched again. Sometimes the plastic molding is just slightly off in size and requires a lot of force (but you don't want that plug loose at all or you'll have a loose connection to your cpu).

Hopefully it lines up and goes together for you without too much more hassle. You're not alone questioning if they fit or not, I've had ones that were ridiculously tight and checked and rechecked the pin pattern to make sure I wasn't somehow trying to attempt the impossible.
 
Solution