Boot up failing on iMac

lakshay1701 Said:

"Boot up failing on iMac: Hi @thelittles, this is also not working The screen itself is not visible, it is not going into safe mode also”

———-

Try an External Monitor:

Connect an external monitor or TV (via the HDMI Port). If that works, then I have a hunch your screen is going dead. So, please report back if it works. Either way, see about getting the screen swapped out.

Get this Screen Serviced, ASAP:

Contact an AASP (Apple Authorized Service Provider) in your local area.

Contact an AASP: 

1. Go Here: Find Locations - Apple Authorized Reseller
2. Click: Service & Support
3. Enter: your location information
4. See: if there is an AASP nearby
5. Contact: an AASP that shows up, and find out more about the services that they offer to fix the screen.

lakshay1701 Said:

"Boot up failing on iMac: [...] yesterday it encountered a problem while booting up, while in verbose mode, it got stuck on "srom rev:9" and it was there for 1-2 hours [...] Kindly help me to restore back my computer. Any help would be highly appreciated. [...] Any of the key combination(s) does not work"

-------

Troubleshoot with External Devices:

Try External Devices:

So, have you tried connecting an external monitor? If not, try doing so, seeing if that makes everything pop up. If it pops up, then reinstall the macOS through that, using that screen.

Or...

Disconnect External Devices:

Disconnect all external devices, and power them off, if they use bluetooth.

lakshay1701 Said:

"Boot up failing on iMac: Unfortunately no, this is also not working”:

———-

Try Booting in Safe Mode:

Hold down shift key upon boot. In Safe Mode, Login Items do not load, and unnecessary caches (temporary files for System Settings) are placed aside and are reset.

Or...

Reinstall the macOS — Back Up First:

You might need to reinstall the macOS. Sometimes, changes are made to your Mac (i.e. uninstalls), and then settings (i.e. for power), become manipulated, technically. So, reinstalling the macOS with place moved items back to where they should be, and will replace damaged system files.

1. First, Back up your Mac:

Create a Time Machine backup of your Mac, so that you can have something to restore your Mac from, should anything go wrong with the reinstall.

2. Then, Reinstall the macOS:

Nothing would be deleted. It's just that items that have become corrupted or deleted, would be replaced or reinstalled back to where they should be. Go Here: How to Reinstall macOS from macOS Recovery - Apple Support

It sounds as though you've done a lot of the right things so far.

What happened when you tried command+R - did it still just show a blank screen?