Led blinks white at 2 second intervals for 20 seconds and then blinks amber in faster irregular flash pattern indefinitely. I tried zapping the PRAM as the Mac startup chord sounded, but it doesn't respond to keyboard input, apparently. Same with trying to start in SAFE MODE, or Recovery Mode. And nothing ever shows on monitor.
Mac mini (M1, 2020)
I think your Mac mini has hardware related issue. Following article could help your issue.
Mac computer status indicator light behavior - Apple Support
You should take your Mac mini to your local retail AppleStore, Genius Bar or Apple Authorized Service Provider to be examined your Mac mini there.
Genius Bar Reservation and Apple Support Options - Apple
Service and Repair Providers for Apple Products - Official Apple Support
I think your Mac mini has hardware related issue. Following article could help your issue.
Mac computer status indicator light behavior - Apple Support
You should take your Mac mini to your local retail AppleStore, Genius Bar or Apple Authorized Service Provider to be examined your Mac mini there.
Genius Bar Reservation and Apple Support Options - Apple
Service and Repair Providers for Apple Products - Official Apple Support
From you description, it sounds like you need to revive and restore the firmware.
see > Mac computer status indicator light behavior - Apple Support
Mac Mini M1 2020 won't get into boot cycle after power on.
