2011 IMAC 27" HDD clicking

[gokuu]

So it only gets THAT FAR before going black? Yikes!

And the PRAM/NVRAM reset didn't work?

Then you are having a much more complicated problem than I thought. Here's what I'm thinking.

(It's not a problem with the ____ because ____)

• Power supply, because then the computer wouldn't even turn on
• Display, because there would be no video at all
• The USB drive, because the createinstallmedia could have partially failed.

When I did the prm/nvram reset, I got to the second chime and the screen turned gray and I let go and it turned black like a minute after

 

[rm5]

Please disregard my comment about AHT, because you need an existing macOS installation for that to work.

You could also try unplugging the iMac for 15 seconds, and then plugging it back in again.

I wonder if this is a GPU issue. I know the 2011 15" and 17" MacBook Pros had this very bad issue with the GPU that would render the machine unusable. Maybe your iMac is suffering the same fate.

Other than that, I unfortunately have no idea how to fix this black screen problem.

The other thing you could try is to hook up the drive AND the SSD to separate external SATA-USB adapters and use Carbon Copy Cloner to clone the HDD to the SSD.

 

[rm5]

Unfortunately the 27" iMac's of that period are plagued with GPU problems.

Here's part of a reply to a post that is dealing with another 2011 iMac:

Original thread: https://forums.macrumors.com/threads/27-2011-imac-black-screen.2274294/

I know this it not the same issue, but it could be a GPU problem, in which case you probably should replace the iMac because a GPU replacement is WAY too difficult I think.

 

[gokuu]

Here's part of a reply to a post that is dealing with another 2011 iMac:

Original thread: https://forums.macrumors.com/threads/27-2011-imac-black-screen.2274294/

I know this it not the same issue, but it could be a GPU problem, in which case you probably should replace the iMac because a GPU replacement is WAY too difficult I think.

Thank you for these. Sorry for the late reply. I will look into cloning the hhd to ssd. Hope that works.

And then try to start her up. And go from there.

Again thanks for all the help. Even if we have a loss, you helped all you could and I’m very thankful for that.

 

[rm5]

Hey gokuu,

I know this has been inactive for awhile, but I just thought of something - did you hear ANY HDD/fan noise when the display went black during the boot process?

Also, maybe the display cable is partially unplugged. You might try to disconnect/reconnect the display.