Unable to restart iMac

brianclark4 said:

My mac model number is: A1312 100.

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Ok...that does narrow things down a bit...thanks for the extra info.

This 27" iMac is older than I was expecting...it's either a 2009, 2010, or 2011 model. What this does tell us is...this 27" iMac almost certainly has a "spinner" HD in it (rather than an SSD).

Given the age & the issues currently being experienced...and what's been tried so far...my guess is the iMac's internal hard drive very likely has "kicked the bucket"...and time for a replacement.

- Nick

Here's a 2nd possibility. With the model number "A1312"...the absolute newest model 27" iMac this can be is a mid-2011.

Earlier we were also told it was running the latest macOS "Mojave". Officially only "Late 2012 & newer" iMac's can run Mojave.

Thus with this iMac being older than 2012...if it was running Mojave...it was installed via a patcher or a hack...and this install may not have been done correctly or it's unstable. Thus the internal HD may not have died...and the issue is the OS install.

- Nick

I think its a m2011 model. I had the GPU replaced mid 2017 if that's any help, also I updated the OS from the apple site itself

Yes the HD is a spinning model, not an SSD

So, it's NOT the latest, but probably High Sierra, you have installed. And the most likely issue is the HD is dead. Do you have a backup? If you have either a clone or even Time Machine backup you can see if it will boot from there, which will be confirmation that the most likely culprit is the internal drive.

I will have a time machine backup, but how di I back up if I cant start the Mac

brianclark4 said:

I will have a time machine backup, but how di I back up if I cant start the Mac

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If you already have a Time Machine backup drive, then if you restart your iMac with the TM drive connected, hold down option, you “may” be able to start up from that. If your internal drive is dead, then you will not have that ability.

Thanks I will give that a try