Help! iMac not booting

[conamor]

Good day,
I have an iMac 2012 27in that I had the HDD replaced by an SSD. It was working fine until recently.

It frozed around 3 times on me during the last week and finally another time today so I told myself I'm gonna go check the console for any reason why it freeze and now its not booting anymore, it gets to the half of the loading apple and then white screen with the message that it did not start properly so I suppose that the SSD went bad.

Of course, I need to get back on it to do a backup.

Would you have any tips to start it? Otherwise I can open the imac again and pull the ssd for further troubleshooting.

Let's hope someone has an idea

Thanks !!

 

[Bigwaff]

Have you tried booting in Safe Mode?

Start up your Mac in safe mode

Starting up your Mac in safe mode may help you diagnose problems with your Mac.

support.apple.com

If that not work, try booting from macOS install external USB media

Create a bootable installer for macOS - Apple Support

You can use a USB flash drive or other secondary volume as a startup disk from which to install the Mac operating system. These steps are primarily for system administrators and other experienced users who are familiar with entering commands in Terminal.

support.apple.com

 

[conamor]

I did try all the combination and none worked. Can't get into the Mac options for reinstalling, etc...
I ended up opening it and getting the SSD out, connected it to an external enclosure to a mbp and it just worked... I suspect the iMac is on its way to the graveyard

 

[conamor]

Now, I am in a big decision. Replacing that iMac with a mac min/studio or imac 24 (I do not like that 24in) or get a regular pc since I made up a bag on apple with the 27 monitor, 5k total (CAD)..

 

[Fishrrman]

Have you tried booting to INTERNET recovery?

REASON WHY I'm asking:
When you boot to internet recovery, it "bypasses" the internal drive completely (in order to get booted).

Try this:
Power down, ALL THE WAY OFF
Press and HOLD DOWN "Command-OPTION-R". Don't let go!
While holding down this key combo, press the power on button.

KEEP HOLDING THOSE KEYS DOWN.
In a while, you should see the msg "starting internet recovery", or "the spinning globe".

You can let go of the keys then.
If you're connecting via wifi, let go of the keys and enter your wifi password (that you use to connect to your router).

It takes a while for the internet utilities to load.
Do you eventually get to the internet utilities?

IF SO...
Open disk utility.
Go to the view menu and choose "show all devices".
Now look at the list on the left.
You should see a listing for your internal drive and the partitions on it.

Click on the first line, then click "first aid".
Do you get a good report?
If so, click on the NEXT line down and repeat.
And repeat, etc.

What results do you get?

 

[jlc1978]

I did try all the combination and none worked. Can't get into the Mac options for reinstalling, etc...
I ended up opening it and getting the SSD out, connected it to an external enclosure to a mbp and it just worked... I suspect the iMac is on its way to the graveyard

Have you tried booting the iMac from the drive you removed from the enclosure as an external boot drive?

At least, if it works on the MBP then at least you should be able to get the data off it.

 

[Nguyen Duc Hieu]

I did try all the combination and none worked. Can't get into the Mac options for reinstalling, etc...
I ended up opening it and getting the SSD out, connected it to an external enclosure to a mbp and it just worked... I suspect the iMac is on its way to the graveyard

Sure, they sell the LCD kit to re-use the LCD panel only. The computer part should go.
Before sending it to the dumpster, you can try testing the easy components for the last time:

As your SSD and Mac OS is working fine on MBP, you can re-use it for the test:

RAM test: Boot the iMac with only 1 RAM stick at a time. Or if possible, boot it with a known-to-work ram stick, different from the ones inside the iMac so far.

If RAMs are fine, then the things left are PSU and GPU, which would be costly to fix anyway. So you can skip them.

Re-using the LCD panel (and frame) as a stand-alone display if you have time and skill. Otherwise just let it go.

 

[conamor]

Have you tried booting to INTERNET recovery?

REASON WHY I'm asking:
When you boot to internet recovery, it "bypasses" the internal drive completely (in order to get booted).

Try this:
Power down, ALL THE WAY OFF
Press and HOLD DOWN "Command-OPTION-R". Don't let go!
While holding down this key combo, press the power on button.

KEEP HOLDING THOSE KEYS DOWN.
In a while, you should see the msg "starting internet recovery", or "the spinning globe".

You can let go of the keys then.
If you're connecting via wifi, let go of the keys and enter your wifi password (that you use to connect to your router).

It takes a while for the internet utilities to load.
Do you eventually get to the internet utilities?

IF SO...
Open disk utility.
Go to the view menu and choose "show all devices".
Now look at the list on the left.
You should see a listing for your internal drive and the partitions on it.

Click on the first line, then click "first aid".
Do you get a good report?
If so, click on the NEXT line down and repeat.
And repeat, etc.

What results do you get?

I tried this too.
The recovery starts, then reboot with the apple logo and gets stuck at around 55%.
I tried it with 2 different set of RAM and 2 different HDD.

Still no success to start that imac!

 

[conamor]

Sure, they sell the LCD kit to re-use the LCD panel only. The computer part should go.
Before sending it to the dumpster, you can try testing the easy components for the last time:

As your SSD and Mac OS is working fine on MBP, you can re-use it for the test:

RAM test: Boot the iMac with only 1 RAM stick at a time. Or if possible, boot it with a known-to-work ram stick, different from the ones inside the iMac so far.

If RAMs are fine, then the things left are PSU and GPU, which would be costly to fix anyway. So you can skip them.

Re-using the LCD panel (and frame) as a stand-alone display if you have time and skill. Otherwise just let it go.

I had 4 sticks, same issue with all of them, I suspect something else. How does it work to use that imac as a monitor for lets say an mbp?

 

[Bray93]

I had 4 sticks, same issue with all of them, I suspect something else. How does it work to use that imac as a monitor for lets say an mbp?

You can use it as a monitor with another Apple device, but you still need to get an OS on it (High Sierra or below for Target Display Mode). So maybe not an option if you can't get an OS loaded onto it.

If you do manage to get an OS on it, you will need to use a Thunderbolt or TB2 cable / relevant adaptors (not Display Port) to connect your laptop and iMac together.

According to official Apple doco, your MBP also needs to be Intel-based (2019 or earlier) and running Catalina or earlier. That said, I have had personal success running Monterey on the 'primary' machine and using TDM.

There is more info here: https://support.apple.com/en-au/105126

 

[Nguyen Duc Hieu]

I had 4 sticks, same issue with all of them, I suspect something else. How does it work to use that imac as a monitor for lets say an mbp?

By gutting the entire computer part, and installing an LCD driver kit.
Carefully check your LCD panel model, and match it with your order. Discuss with the seller if needed. The board will be the same, just change the cable. Need proper thermal solution for the main chip on the board, or it will fry easily.

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