Mac Mini 2018 HDMI port not working?

[Slippery Gimp]

I have a Mac Mini 2018 and it’s connected to my 2018 LG smart tv, just like it has been since new. Nothing has changed in that regard.

I recently turned the Mac on from being completely off, and the screen went black. I expected the Apple logo to appear next as part of booting up, but instead it gave me the ‘no signal’ screen that my tv says when it’s not detecting any input. I’ve tried different cables and different ports, but no difference.

Is my HDMI port broken? I’ve read about this happening when the OS has updated, but the posts were from 2020 so I’m not sure if this is still happening.

 

[Ben J.]

Several things might be happening; like the mac might have lost count on which display is connected. This often corrects itself if you simply disconnect and reconnect the hdmi cable on the mac while the mac is running. So make sure your tv is set to 'hdmi1' input or similar and unplug and replug the cable on the mac. The mac might be sending video out on a TB/usb-c port, so you could also disconnect anything connected there first.

That's a couple of things I'd try first. Can you tell if the mac has started up at all? Power light on, external devices showing activity etc.

 

[Slippery Gimp]

I’ll try (although I think I have) disconnecting the HDMI cable as you say and see what happens.

And yes, the power light is on and it does the start up chime, then goes to the ‘no signal’ screen my tv displays when nothing is detected.

 

[Fishrrman]

Something to try, may not help, but won't hurt anything:

With the power (to the Mini) off, put your finger on the option key and KEEP HOLDING IT DOWN for a while after you press the power on button.

This key combo invokes the "startup manager".

Does it also produce an image on the tv?
If it does, just select the internal drive and continue.

 

[Slippery Gimp]

Something to try, may not help, but won't hurt anything:

With the power (to the Mini) off, put your finger on the option key and KEEP HOLDING IT DOWN for a while after you press the power on button.

This key combo invokes the "startup manager".

Does it also produce an image on the tv?
If it does, just select the internal drive and continue.

Well I don’t know what happened, but I did as you said and it booted up no problem at all! I didn’t have to select any drives or anything, it literally just booted up. Although once logged in it said something like, “Your computer didn’t shut down properly etc”. Maybe someone (not me!) didn’t shut it down properly and that’s what caused the problem. Oh well, brilliant, thanks again.