Question New build not turning on when CPU power cable is plugged in ?

Oct 14, 2022
Hi all,

Trying to troubleshoot why my new computer won't turn on. Specs are below. When I plug just the motherboard power cable into the power supply, the computer turns on (RAM lights up, CPU and case fan start running) and CPU debug LED turns on as expected.

When I then plug the CPU power into the psu, the whole thing won't turn on. I've tried using two different CPU power cords so I don't think those are the issue. I need some help figuring out if it's actually a CPU issue or if it is a motherboard or PSU issue.

CPU - Intel Core i7-12700K 3.6 GHz 12-Core Processor
CPU Cooler - Cooler Master Hyper 212 RGB Black Edition 57.3 CFM CPU Cooler
Motherboard - MSI MAG Z690 TOMAHAWK WIFI DDR4 ATX LGA1700 Motherboard
Memory - G.Skill Trident Z Neo 64 GB (4 x 16 GB) DDR4-3600 CL16 Memory
Storage - Samsung 980 Pro 2 TB M.2-2280 PCIe 4.0 X4 NVME Solid State Drive
Video Card - EVGA XC GAMING GeForce RTX 3060 12 GB Video Card
Power Supply - Corsair SF750 750 W 80+ Platinum Certified Fully Modular SFX Power Supply
Power Supply Cable Extensions - Antec Sleeved Cable - Power Supply Cable Extension Kit with Extra-Sleeved 24 PIN 8PIN 6PIN 4+4 PIN with Combs- Black (11.8inch/30cm)
Case - Phanteks Enthoo Pro ATX Full Tower Case