Pc build alienware

So my power supply died on me and I bought a new one. On my Alienware motherboard, a 2 by 2 connection labeled “atx_cpu” on my new power supply I bought, (power spec 650 W semi modular) it does not contain a 2 by 2 connector. My Alienware flashes yellow in increments of 2 but doesn’t turn on. Is that the issue or is there something else?