... caused by my own tinkering.

Edit: SOLVED! simply disconnecting the drives and then adding them one by one (starting with the windows drive, dont know if thats important) did the trick

(Sorry if this is the wrong community for HELP ME posts like this, couldnt find one that fit the bill better)

So recently i made up my find about switching my self-build from 2018 from win10 to linux mint, though i first wanted to try it out in dual-boot. I created a bootable usb and started the installation process to a partition on an ssd thats seperate from the hdd that holds my windows installation. Installation worked out fine, PC powered down from live usb mint and booted into mint from my petition (worked fine). Afterwards i powered it down to check if i could access windows.

After turning it on, instead of showing the GRUB OS selections screen, it just showed a GRUB command window, and my keyboard wasnt recognized.

Powered down, disconnected the ssd in hopes of forcing windows to start, no luck. Entering BIOS via f2 or del on startup didnt work either (probably because fast boot was enabled), tried every available usb-port for the keyboard to either get into BIOS or at least get GRUB to respond. Nothing.

After shopping for solutions online, i cleared CMOS via the button on the mobo. I hoped it would either help the keyboard get recognised by GRUB, or at least deactivate fast-boot. But after powering the pc on again, my screen stays blank and the indication LEDs DRAM and BOOT are glowing.

I already tried taking out one of the two ram-sticks and placing the remaining one in each of the slots, then did the same withe other stick. No effect on the DRAM LED.

Im not quite at wits end here, but i thought before i continue to haphazardly apply fixes found online (and probably making it worse) i would look wether anybody here has good ideas for what steps to take next.

Here is my hardware:

Mobo: nzxt n7 b550

cpu: amd ryzen 5 5600x

gpu: amd rx 580 sapphire nitro+

psu: be quiet pure power 11 500W

ssd: kingston 240gb (linux boot)

hdd1: barracuda 1tb (win10 boot)

hdd2: wd blue 2tb (mostly games and stuff)