iMac 27 5 K won't start up

Greetings jimfromoc,

Thanks for using the Apple Support Communities!

I understand that your iMac is not starting up as expected and we know how frustrating and concerning issues like this can be.

To begin troubleshooting, I suggest reading over the information in the following article.

If your Mac won't turn on - Apple Support

If the issue continues after working through the previous information, try starting in safe mode as described in the next article.

Try safe mode if your Mac doesn't finish starting up - Apple Support

Have a great day!

HI

did your problem resolve? I have exactly same problem.

LOok ok at my post