Mac Mini not booting (fan is on, no HDMI signal)

[DubheasaNi]

Hello,

I'm having a very strange problem with my Mac Mini 2014. My Mac Mini was using High Sierra and I believe it is possible it was having a software update when I had a power outage yesterday.

When power was restored, I've been unable to get it to properly boot.

• When I turn it on, the front light goes on and I can hear the sound of a fan; however, there is no HDMI signal and no startup chime whatsoever.
  
  
• When I turn it on and hear the fan, I tried hitting the caps lock key on my USB Apple keyboard and unfortunately the LED does not go on, so I'm unsure if the keyboard is even being recognised.
  
  
• I've tried resetting the PRAM, but I don't think it's recognising the keyboard and I hear no chimes.
  
  
• I can't reset the SMC, because the instructions state to wait 5 seconds after plugging it back in to restart it; however, the Mac Mini starts automatically the moment I plug it in.

I am at a loss at what to do next. I purchased a Thunderbolt cable and it will be here in an hour or so, so I can maybe connect it to my iMac as a drive, but with the keyboard not appearing to be working I'm not sure if that will even be possible.

I appreciate any suggestions!

 

[CoastalOR]

Try Recovery to reinstall the macOS. If that does not work then try Internet Recovery.
https://support.apple.com/en-us/HT201314
https://support.apple.com/en-us/HT204904

 

[DubheasaNi]

Try Recovery to reinstall the macOS. If that does not work then try Internet Recovery.

Thank you: unfortunately none of this works.

Recovery requires that I urn on your Mac and immediately press and hold Command (⌘)-R

The problem is I do not believe it is recognising the USB Apple keyboard because when the keyboard is plugged in, the caps lock light does not come on when pressed.

None of these hold down key commands have worked so far and that is another source of my suspicions. I’ve tried to reset the PRAM for example and it doesn’t seem to have had any impact, no chime was heard.

Similarly, there’s no display signal coming from the HDMI to the monitor. I’ve tried two monitors that I can confirm work when I connect my laptop. When I plug in the Mac mini, there’s no signal, it’s just a blank screen.