Not able to boot from any device on Mac Mini 2011

Hello,

I have an issue with my Mac Mini 2011 where after failing to update it to Big Sur using OCLP, it now does not allowing me to boot from any device.

I made a bootable installer for Mac OS High Sierra with another Mac, but when I turn on the computer and press the option key to bring up the boot options, the icons for the drive appears. But nothing happens when I try to click the drive to reinstall the OS. It shows the click animation and I can select a WiFi network, so I know that it is not frozen, it just refuses to boot from any medium.

I also erased the internal drive completely for a fresh install from the OSX Recovery Disk Utility, so I cannot try to boot into the internal drive either.

Anyone has other ideas I can try?