Question Can't get motherboard to power on

[JBateman]

I'm building a pc for the first time and I can't get the motherboard to power on. I'm on my second psu and second motherboard with no improvement so I don't know what else to try. I've gone through many debug steps including this whole no POST checklist. When I try the step towards the end about pulling everything except CPU and cooler I don't get the intended results. I don't get any beeps about missing memory. I've yet to see any real life on this motherboard or the last one. No LEDs, no sounds, no fans turning on.

I have tested my psu and I'm fairly sure it's good. I did the paper clip test and measured the voltages on all the pins and they looked good. I'm pretty sure my cpu is installed correctly and I'm reasonably certain I have a roughly 'correct' amount of thermal paste. I have tried hooking all components up (ssd, gpu, fans, case headers) and my last test was with only cpu and cooler. On that attempt the only connections on the motherboard were two 8 pin cpu headers, the 24 pin ATX connector and the cooler fan plugged into 'PUMP_FAN1'. In that test I can measure 3.3V on the power switch pins but when I short them together I don't get anything.

My hardware is all new except the CPU which I got used on Amazon. I previously tried a MSI Pro B650 Wifi board but figured it was the problem and returned it. Now my new board is doing the same thing so it seems like that was not the case.

CPU: AMD Ryzen 5 7600X
Cooler: Deepcool AK400 Zero Dark
MoBo: MSI Mag B650 Tomahawk Wifi
RAM: GSkill Ripjaws S5 DDR5
GPU: RX 7900 XT
Other fans: random NZXT fans I had lying around
PSU: Corsair RM750e
Case: Fractal Design North
Storage: Crucial P5 Plus 2TB

Here is an image showing the motherboard outside the case hooked up to the minimum connections mentioned earlier.

mobo hosted at ImgBB

Image mobo hosted in ImgBB

ibb.co

 

[CountMike]

I'm building a pc for the first time and I can't get the motherboard to power on. I'm on my second psu and second motherboard with no improvement so I don't know what else to try. I've gone through many debug steps including this whole no POST checklist. When I try the step towards the end about pulling everything except CPU and cooler I don't get the intended results. I don't get any beeps about missing memory. I've yet to see any real life on this motherboard or the last one. No LEDs, no sounds, no fans turning on.

I have tested my psu and I'm fairly sure it's good. I did the paper clip test and measured the voltages on all the pins and they looked good. I'm pretty sure my cpu is installed correctly and I'm reasonably certain I have a roughly 'correct' amount of thermal paste. I have tried hooking all components up (ssd, gpu, fans, case headers) and my last test was with only cpu and cooler. On that attempt the only connections on the motherboard were two 8 pin cpu headers, the 24 pin ATX connector and the cooler fan plugged into 'PUMP_FAN1'. In that test I can measure 3.3V on the power switch pins but when I short them together I don't get anything.

My hardware is all new except the CPU which I got used on Amazon. I previously tried a MSI Pro B650 Wifi board but figured it was the problem and returned it. Now my new board is doing the same thing so it seems like that was not the case.

CPU: AMD Ryzen 5 7600X
Cooler: Deepcool AK400 Zero Dark
MoBo: MSI Mag B650 Tomahawk Wifi
RAM: GSkill Ripjaws S5 DDR5
GPU: RX 7900 XT
Other fans: random NZXT fans I had lying around
PSU: Corsair RM750e
Case: Fractal Design North
Storage: Crucial P5 Plus 2TB

Here is an image showing the motherboard outside the case hooked up to the minimum connections mentioned earlier.

mobo hosted at ImgBB

Image mobo hosted in ImgBB

ibb.co

Why Pump_Fan header when using air cooler ?
Any fans connected to CPU_FAN ?

 

[JBateman]

Why Pump_Fan header when using air cooler ?
Any fans connected to CPU_FAN ?

Good catch. The motherboard I had tried previously had the fan pins arranged slightly differently so I accidentally hooked this up to PUMP_FAN since it's located where CPU_FAN was on the old board. I switched it to CPU_FAN in my breadboard setup but it didn't change anything. Still completely unresponsive when I short the switch pins.

 

[JBateman]

Update:
I tried switching the cpu fan with another fan to see if the cooler was the issue but that didn't fix it. Then I took the cpu out of the board and tried and the board turned on. The fan on the cooler turned on and the cpu and dram debug lights on the board lit up. I still had one stick on ram installed.
This makes me think the the whole problem is the cpu. I haven't seen anything online to suspect that a faulty cpu could cause this sort of issue but it's the only thing I can isolate. I'll try and get another of the same cpu and see if that will boot up.