Question PC won't start after motherboard swap

[Ryan237]

I have a secondary PC that used to work perfectly fine. These WERE the components (old motherboard):

CPU: Ryzen 7 2700x
GPU: GTX 1050
RAM: Gskill Ripjaws DDR4 3200
MOBO: MSI MAG x570s Tomahawk Max Wifi
PSU: EVGA 650 BQ 80+ bronze
Case: Montech X1

I recently swapped motherboard from my main PC to that secondary one. The motherboard was this one:

MOBO: Asus ROG Strix b450-f Gaming

There was nothing faulty with this motherboard. I was simply swapping because the x570 had wifi and some other compatibility stuff for the future.

Now, I tried to boot my secondary pc (using front panel power switch) and get nothing, not even boot LEDs or beeps. There are a few indicators that I know are helpful but I have been unable to figure anything out.
1) The motherboard LEDs light up. To me, this means it gets proper power. I checked the 24 pin and it looks fully seated.
2) I cleared the CMOS by shorting the CLRTC pins with a screwdriver. This temporarily jolted the case fans with electricity. They didn't even do a 1/4th rotation, they just started to spin for a milisecond.
3) I turned everything off and disconnected the power cable. I then reconnected everything, turned on the PSU, and upon attempting to use the power button on the front panel--the fans jolted again. This was tested multiple times, and no matter how long I waited, the first time I attempted to power the PC with the front panel switch, the fans would jolt. HOWEVER, they do not move again after trying to click the power button again. The PSU must be turned off, and then turned back on, for this to happen.
4) I reseated both the 24 pin MOBO power cable, and the 8 pin CPU power cable, both changing nothing. Still the MOBO LEDs work, and the fans jolt.
5) Checked front panel connectors for POWERSW and ensured pins were in right spots. Reseated it, and tried it in both positions (arrow on GRND pin and arrow on other pin)
6) Did paper clip test on PSU -> success. Fan on PSU spun.

If anyone has any thoughts, I would greatly appreciate it. I will be monitoring this thread closely.

EDIT:

Is it a compatibility issue? I was running the Asus MOBO with a Ryzen 5800x when it was working fine. As a reminder, it doesn't work with the 2700x now. Now, plugging it into pcpartpicker, it says there could be an outdated BIOS on the MOBO. I already cleared CMOS though, and I haven't been able to boot to look at the BIOS.

 

[Ralston18]

Based on the context of your post my understanding is that you likely used the boot drive (C:\) from the original motherboard for the new motherboard.

Is that correct?

"Moving" a boot drive rarely works.

If it does happen to work then there will likely be ongoing problems...

With a new motherboard you need a new/clean install.

FYI:

https://forums.tomshardware.com/faq/windows-10-clean-install-tutorial.3170366

Also, for the record, make and model disk drive(s)?

Disk drive(s) capacities and how full?

 

[Ryan237]

Based on the context of your post my understanding is that you likely used the boot drive (C:\) from the original motherboard for the new motherboard.

Is that correct?

"Moving" a boot drive rarely works.

If it does happen to work then there will likely be ongoing problems...

With a new motherboard you need a new/clean install.

FYI:

https://forums.tomshardware.com/faq/windows-10-clean-install-tutorial.3170366

Also, for the record, make and model disk drive(s)?

Disk drive(s) capacities and how full?

Thanks for replying!

Yes, the original secondary PC boot drive is the same drive being used. I could format it on my main PC and do a clean windows install with a flash drive, I'll let you know the results after that happens. I suppose I thought it would at least boot my pc and fail in POST.

Right, forgot to include that. I have a singular Samsung 850 Evo 500 Gb.

EDIT: Everything I'm finding is telling me that even without a boot drive, the computer should POST. I would like to not wipe the drive, and since it probably is not causing this problem, could you explain why a missing boot drive will prevent power from reaching components?

 

[Ryan237]

Thanks for replying!

Yes, the original secondary PC boot drive is the same drive being used. I could format it on my main PC and do a clean windows install with a flash drive, I'll let you know the results after that happens. I suppose I thought it would at least boot my pc and fail in POST.

Right, forgot to include that. I have a singular Samsung 850 Evo 500 Gb.

EDIT: Everything I'm finding is telling me that even without a boot drive, the computer should POST. I would like to not wipe the drive, and since it probably is not causing this problem, could you explain why a missing boot drive will prevent power from reaching components?

Turns out the BIOS clear wasn't working but that's what it took. After BIOS clear, I updated the BIOS and reinstalled windows. Works fine after that.