I want to install os 10.12, not 10.12.6. Is there any reason why 10.12 doesn't seem to be available? Previous attempts to upgrade (from 10.11.6) killed my iMac and I had to restore back to 10.11.6.

In the App Store search for "macos" which will show you the most recent version of macOS that is compatible with your computer. If you want to get a specific version of macOS or to manually create a bootable macOS USB installer, then check out this Apple article which has links to OSX 10.11+.

https://support.apple.com/en-us/HT201372

Make sure to have good verified working backups before upgrading just in case something goes wrong.

Updates for 10.12 are still available. And yes, you would have to have 10.12 installed to use them. I never answered your question as to why 10.12 is no longer available. It's because 10.12.6 contains all the updates/fixes since 10.12's release and it makes no sense to have people install 10.12, then have to update it.

You never explained how upgrading to 10.12.6 "killed" your iMac.

If you have installed OSX 10.12.6 before, then you should be able to boot into Internet Recovery Mode using Command + Option + R which will give you access to the latest compatible version of macOS for your computer.

Run EtreCheck and post the report here using the "Additional Text" icon which looks like a piece of paper.

It might be a good idea to run DriveDX to check the health of your hard drive(s). Post the DriveDX report here using the "Additional Text" icon which looks like a piece of paper. Post the DriveDX report even if the drive is reported as healthy since the report may contain some clues. If you have a Fusion Drive, then post the report for the SSD and the hard drive.

Because this 'thread' has been answered (or solved = green symbol) a new one should be opened.

Be sure to use definite terms of what your mac is, by build year and configuration identification.

(This was intended to be directed to the original author; error recognized only after posting

too late to re-direct the content to DanLevitan. ~The idea remains valid. None of my Macs are

newer than mid- to late- 2012 and are very repairable.)

There may be, by now, some other issue with the Mac that could be problematic. And sounds like

it may have been an issue of oversight back when new; or maybe a weak part. This is an unknown.

Since you state the product is '2016' ~ was that information obtained from original documentation?

If it were identified by purchase date alone, it may be that it's older than a calendar date. So details

are important. If the unit were under an extended AppleCare protection plan and submitted for

repair, it would have been assigned an incident or repair order number. Looking back, that may help.

Especially should you have revisited this situation at least once, on record since the date of purchase.

Please start this as a new ASC discussion, and focus on the original specifications and build info;

and any further upgrade past the as-shipped macOS, which you knew to have occurred. ~ Or seek

authorized Apple service who can provide complete diagnostic & repairs. Or this time, maybe not?

A three or four year old Mac shouldn't be a problem to troubleshoot; an independent authorized

Apple service (sometimes part of independent reseller) should probably be considered for repair.

Good luck & happy trails!🌞

10.12 is no longer available. 10.12.6 was the last version and the only one that would be available.

Then what you have are updates to 10.12, not a full 10.12 installer.

As has already been stated, if you need a full installer, the only thing available is 10.12.6

No. The Combo update requires 10.12.x installed and updates any version to 10.12.6. A "Combo" of updates.

Does this mean that I'm stuck on 10.11.6 forever?