New Build - Struggling With CPU Power

It's been a long few days. Between Christmas and New Years Day, I built a new PC. The components:

ASUS Prime X670E-Pro WiFi motherboard
AMD Ryzen 9 79003D 12 Core 24 Thread CPU
ASUS TUF Gaming GeForce RTX4070Ti OC 12GB GDDR6x GPU
WD Black SN770 2TB PCIe Gen4 NVMe M.2 SSD
Corsair Vengence 64GB DDR5 5600MHz RAM
DeepCool LS720 High Performance 360mm CPU Liquid Cooler
Phanteks Eclipse G360 Air Mid Tower Case
ThermalTake Toughpower GF3 1000W 80+ Gold Full Modular ATX Power Supply

All put together, I could not get it to post. There was no display to the monitor, no diagnostic beeps, yet all the components lit up all pretty like. The cooler fams were spinning. (Lesson learned ... keep fingers away from spinning fans)

Took it apart, pieced things together one by one and at in no stage did I manage to get anything. First ruled out the RAM, as it wasn't listed in ASUS's list of qualified RAM modules. Thinking that may have been the cause, so replaced it with Kingston Fury Beast 64GB DDR5 5600MHz CL36 (KF5563C36BBEK2-64).

It was pointed out to me in another threat (this post originated from an extensive cross thread here), that I should try to connect the CPU power. I hadn't done that, I had originally just connected the board's ATX power. The mother board has 2 8 pin power connectors labelled ATX_12V_1 and ATX_12V_2 respectively. My PSU has two banks of 2 8 pin CPU/PCIe connectors in the rear. The PSU cam with two cables, 8 pin, labelled CPU. I connected each cable to the board's ATX_12V connectors, and after a lot of cursing, fed them through whatever crevice I could find to route them to the PSU (short cables and connections couldn't be any further away from each other). One snapped into the back of the PSU (CPU port), however, I am unable to plug the second one in. For some reason, the two cables are not the same. Although 8 pin, unlike the first cable, it has a wide (x2) retainer clip, whereas the other cable was just a narrow single clip. None of the clip receivers on the back of the PSU are wide enough to accept a double wide clip.

Any advice on what I should/can do? I'm assuming that I'm trying to use this cable for a purpose it's not intended for, as usually it's build so as to not sticks things where they shouldn't go. Clearly this isn't supposed to go where I want it. Is this not an appropriate cable considering it is one of only two cables marked CPU? As asked in the other post, is this second connection needed. I'm assuming yes. But what are my options? Can I just rummage through my spare computer parts to see if I can find another appropriate CPU cable? The manual says not to. Or am I doing something terribly wrong?

Do any of the diagnostic LEDs on the motherboard light up? Did you plug in the monitor cable into the GPU and not the motherboard? Those CPU Power connectors aren't always needed, but it's certainly better to plug them in too. Usually it's 2x x8. Those cables should come with the PSU and usually have CPU printed on the cable connector.

Hi Alex, thank you for reaching out. This build has been a nightmare plagued by problems, but by far this is the worst. The others are a power switch that turns the computer on, but not off, and three chassis fans that don't run when power is on (maybe its supposed to be like that? Dunno as I don't know what to expect.)

The board has no diagnostic LEDs to my knowledge. But the board's fancy RGB, the memory sticks, the cooler, all light up nicely. I have tried the monitor plugged into both the GPU (when I realized there was a problem). During testing, the GPU was removed and I tried to feed the monitor through the onboard graphics, but still no signal. Someone told me that may not work because of BIOS settings haven't enable the onboard, but I hold little faith in that. After all, if you didn't have a graphic card, how would one utilize the onboard one?

As I said in my OP, I have two cables, both marked CPU. All 4 ends are 8 pin. The difference is in the connector itself. One has a retainer clip that is too wide to be received into the back of the PSU. See the image attached. The connector on the right in the image appears to be a double clip, whereas the one on the left, that fits into the back of the PSU, has a single clip. All the PSU connectors have single receivers. I want to feel that it is an anomaly and shouldn't be like that. The two cables I would think would be identical, and if they were, I wouldn't be asking what to do.

Your motherboard does have diagnostic LEDs. The 4 small ones in the top right. Check those.

Are you saying you only have 2x 8-pin CPU power cables but you need 2x 6-pin, resp 12-pin?

Hi Alex, I appreciate your support. Good news, after a total rebuild, I managed to solve all my problems and got things working (knock on wood.)
The diagnostic lights were hidden behind some cables, but know that I know they are there, they proved useful.
As far as the cables go ... I needed 2 eight pin cables to connect the CPU power. I had those. What I hadn't realized was that the connectors at each end were different, only in terms of their retaining clips. One end has a narrow (single) clip, where the opposite end has a wider (double) clip. I realize now they can only fit one way. The double clip end has to connect at the motherboard, and the single clip at the PSU. Of course the single clip will still connect at the motherboard, but that leaves the double clip at the PSU, which will not work. I had to reverse the cables.

A newbie mistake!!

Awesome, glad you figured it out!