Upgrading to Sierra from Mountain Lion; Stops halfway after restart and suggests Diagnostics. New ssd cause?

Question

Level 1

4 points

Upgrading to Sierra from Mountain Lion; Stops halfway after restart and suggests Diagnostics. New ssd cause?

I have a late 2009 27" i7 16gb iMac. Yes it's old. But I put in an EVO 860 500gb and its quick enough to run anything i throw at it.

Trying to upgrade from Mountain Lion to Sierra from App store.

Once restarted, it stopped half-way with the error message:

To use Apple diagnostics to check your Mac hardware, shut down, press the power button and immediately hold the ‘D’ key until diagnostics begins.

Quit the installer to restart your computer and try again"

Is this because of my new HDD? I actually had no choice and HAD to replace a faulty HDD so decided on SSD. Mountain lion installed without a hitch from bootable USB.

I have time machine backup on ext.

Just wondering if anyone can suggest the next step, besides restoring from time machine? How can I upgrade?

Thank you

iMac, OS X Mountain Lion (10.8.5), Late 2009 27" i7 16gb Ram

Posted on Oct 12, 2018 1:21 PM

Reply

Answer 1

Top-ranking reply

mattmediac Author

Level 1

4 points

Oct 13, 2018 7:14 PM in response to mattmediac

Okay so I found the problem and solution; bad ram.

I ran a Diagnostic using the applications install dvd, booted holding 'D' and ran a diagnostic. It found faulty ram.

Faulty ram code: 4MEM

Replaced it and ran same diagnostic.

This time it failed sensor test due to new SSD (4SNS). I use Macs Fan Control for this. But at least the ram was happy.

Replaced faulty Ram module, rebooted, downloaded Sierra again from Mountain Lion on App store and it installed without a hitch. Seems to be running good!

Reply

Answer 2

leroydouglas

Level 10

199,452 points

Oct 12, 2018 1:34 PM in response to mattmediac

mattmediac wrote:

I have a late 2009 27" i7 16gb iMac. Yes it's old.

Trying to upgrade from Mountain Lion to Sierra from App store.

Once restarted, it stopped half-way with the error message:

Sierra?

If this is an early 2009 Sierra will not install. Verify you meet all the requirements

macOS Sierra - Technical Specifications

macOS High Sierra - Technical Specifications

Reply