(late 2012 iMac) Black Screen 21,5"

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Level 1

11 points

(late 2012 iMac) Black Screen 21,5"

Hello,

I've tried to change the HDD of this iMac to an SSD and also cleaned it, after i was done (i fully disassembled it and cleaned it with compressed air) I've noticed that i have broken the display ribbon cable which I have later replaced, but the Mac still wouldn't show me any picture, then I connected it to an external display where it posted after like 4 minutes, i got into the EFI installed Windows10 then when it was time for the GPU drivers the picture just died, nothing was on the external display. I thought maybe it hated windows or something so i started installing MacOS, which I haven't finished yet. But it still wasn't displaying to its own screen, even after reconnecting it many times, it only displays to an external display, what could be the problem? I live in Hungary where iMacs aren't really popular so there's no nearby repair shop (I gave it to one, but they didn't even know how to disassemble it) The reason I tried to install Windows and MacOS that maybe they will see the iMacs own display.

As I know it the display is not damaged, and the iMac still functions as normal, although the fan is really loud but I think its cause of no OS

Specs of this machine:

-i5-3330S

-GT640EM

(I also don't really know how Macs work I've always been a Windows and Samsung user, I just got this Mac as a gift from my grandma's friend)

Thank you for any of your suggestions!

Regards: D.

Earlier Mac models

Posted on Apr 14, 2024 8:05 AM

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Answer 1

BDAqua

Level 10

239,219 points

Apr 14, 2024 12:30 PM in response to DavidJms

Sorry, APFS is Apple's new File System, won't work on your older Mac.

Windows Win key = Mac CMD key or ⌘

Windows alt key = Mac Option key or ⌥, also called alt key on Mac sometimes.

Start up from macOS Recovery

To start up from macOS utilitRecovery, turn on your Mac and immediately press and hold one of the following combinations on your keyboard. Command-R is generally recommended, especially if you never installed macOS Sierra 10.12.4 or later… How to reinstall macOS - Apple Support

Command (⌘)-R... Alt+r on Win KB.

Install the latest macOS that was installed on your Mac.

Option-⌘-R... Windows+Alt+r on Win KB.

Upgrade to the latest macOS compatible with your Mac.

Shift-Option-⌘-R... SHIFT+Windows+Alt+r on Win KB.

Install the macOS that came with your Mac, or the closest version still available.

Of course you may need to make a USB installer...

Create a bootable installer for macOS - Apple Support...

Create a bootable installer for macOS - Apple Support

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Answer 2

BDAqua

Level 10

239,219 points

Apr 17, 2024 7:11 AM in response to DavidJms

And you say the internal display is working now?

You need a better browser than Safari on 10.8.x

Thanks to A Brody, Browsers by Mac operating system…

Browsers by Mac operating system - Apple Community

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Answer 3

DavidJms Author

Level 1

11 points

Apr 14, 2024 12:00 PM in response to BDAqua

Sorry what is APFS, also what is Option -R in a windows keyboard (I can look it up, but idk if what they say is right) is restore mode this: ] Cause if it is, then it does boot to it, on the external display only.

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Answer 4

DavidJms Author

Level 1

11 points

Apr 16, 2024 10:24 AM in response to BDAqua

NOW ITS got image again maybe it didnt like my gaming monitor, I hooked it up to my tv and now its posting again

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Answer 5

BDAqua

Level 10

239,219 points

Apr 14, 2024 10:10 AM in response to DavidJms

The LVDS cable would be 1st suspect.

Then google...

https://www.google.com/search?q=ifixit+%28late+2012+iMac%29+Black+Screen+backlight&client=opera&sca_esv=0bc39af9d1d15b37&ei=mQ0cZoShONnJ0PEP2rComAg&ved=0ahUKEwjE0af0mMKFAxXZJDQIHVoYCoMQ4dUDCBA&uact=5&oq=ifixit+%28late+2012+iMac%29+Black+Screen+backlight&gs_lp=Egxnd3Mtd2l6LXNlcnAiLmlmaXhpdCAobGF0ZSAyMDEyIGlNYWMpIEJsYWNrIFNjcmVlbiBiYWNrbGlnaHQyBRAhGKABMgUQIRigATIFECEYoAEyBRAhGKABMgUQIRigAUinRlDiCFjvQHABeACQAQCYAXGgAZcHqgEDMy42uAEDyAEA-AEBmAIKoAKvB8ICDhAAGIAEGIoFGIYDGLADwgILEAAYiQUYogQYsAOYAwCIBgGQBgSSBwMzLjegB7kt&sclient=gws-wiz-serp

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Answer 6

DavidJms Author

Level 1

11 points

Apr 14, 2024 10:35 AM in response to BDAqua

Do you think that will be the problem? how can I test to make sure it really is before replacing it, also is it hard to replace?

also its GPU might be faulty, cause whenever I try to install drivers to it the picture just dies, then I'll have to install windows again.

Thanks

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Answer 7

BDAqua

Level 10

239,219 points

Apr 14, 2024 11:20 AM in response to DavidJms

David, I haven't seen an inordinate amount of failures o that card in Macs, but I do hold my breath when I hear Nvidia.

Does it bot to Restore Mode???

Start up from macOS Recovery

Option-⌘-R

Upgrade to the latest macOS compatible with your Mac.

In Disk Utility>View, select Show all Devices, highlight the top left entry.

Run Disk First Aid on all items in the left panel, from top down.

APFS won't work for Sierra or earlier, Sierra or earlier needs MacOS Extended Journaled. High Sierra won't work for APFS on earlier Macs.

Yes, the fans running full speed is a failsafe for when the OS is not checking heat.

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Answer 8

DavidJms Author

Level 1

11 points

Apr 16, 2024 6:36 AM in response to BDAqua

MacOS is still installing, but when and it doesnt seem like its gonna install anytime soon, maybe I'll have to make a bootable usb cause the OS X downloader EFI doesnt work for me... But after MacOS installs, should I connect the internal screen while still being plugged into the external screen so if I go to this menu it might say that the is two display (the internal and the extrenal)?

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