[SOLVED] Tried changing GPUs, now stuck on BIOS as SSD not showing on boot priority, but in storage section

[Teasome]

Hi, new user here in a bit of a pickle.

I try booting up my PC but it always goes to the BIOS only. MSI EZ debug LED white on BOOT. BIOS recognising storage, but not showing in boot options.

-This all started when my new Nvidia Geforce RTX 3080 TUF arrived so I tried simply swapping it with my current Geforce 970. I think i've messed up with the power supply, as I did not fully connect the power to the new GPU (970 has 8pins pcie, 3080 has 16pins).
-So, I tried connecting all 16 pins with the daisy-chained pcie cable, but that didn't work ( saw on a YT video that this is not a good idea) , so I connected another pcie cable to the power unit (Corsair 850W gold 80+) and powered up again. However, while the graphics card now had sufficient power, it would not boot past the BIOS.
-So, tried going back to scratch with my old graphics card etc(POC working absolutely fine before this), but it still does not want to recognise my SSD as a boot drive. I tried resetting the Motherboard (removing battery, waiting and restarting), but still no recognition.
-I have swapped my SSD and HDD to the SATA slots 1 and 2, no luck. I removed my SSD (which has the operating system) and connected via a USB SSD adapter to see if it could boot as a UEFI Hard Disk USB but no luck there either.

Is there a chance I have somehow damaged the SSD/Motherboard while trying the new GPU? Any recommendations on further actions/diagnostic methods to see what might be causing the issue?

Specs
-Motherboard: MSI z490 a pro
-GPU: Geforce gtx970 (trying to upgrade to Geforce RTX 3080)
-Power Supply: RM860 Corsair 850w gold 80+
-RAM: (2x16GB) Corsair 163301 Vengeance LPX 32 GB
-Storage: MAIN BOOT- Samsung 860 EVO 1TB , with 1TB HDD (was old host of the OS before changing to SSD) and 1TB M2 Samsung SSD (keeps my games on, nothing else)

Might not have explained that well so please ask if there's any other information that would be useful that I have missed? I don't know how to add photos but If I figure out how to I'll post what I see.

Many thanks for your time.

 

[Teasome]

OK, SO MY FRIEND CAME OVER AND SAVED THE DAY. HERE IS THE SOLUTION THAT WORKED FOR ME, FUTURE READERS. GOOD LUCK!
Go into the bios of the motherboard make sure CSM mode is enabled.
Set the detection to Legacy op rom \ Uefi mode.

Enable detection of legacy devices if it exists as an option in your bios settings.


Go to your booting options, or boot order list of devices to set.
The first list you see should have up to six devices for selection that you can set in a booting order.

Scroll down the page and you will see another two options for selecting boot devices.

Click on number 1 and you should see the ssd drive listed there select it.

Save the changes you made in the bios before you exit it.

Here is the thread I got this from; https://forums.tomshardware.com/threads/ssd-not-detected-in-bios-please-help.2669749/