I purchased used iMac over auction. The iMac seems to show no picture. Could this be the display pin issue or it has the like of faulty GPU?

Since these iMacs don't have screen mirroring by default, is there any way to do that to see if its GPU or display issue. I am attaching the pictures below:

enter image description here enter image description here

More then half screen is black.

1 Answer 1


Without putting hands on, it's impossible to know for sure if it's a GPU or an LCD issue. However, a screen that has a delineated bright area and a dead area will most likely be the display panel and not the GPU.

It's not clear what you mean by a "display pin issue," but if you're referencing an issue with the display LVDS cable, then no, it won't be related to a faulty cable.

If you have another Mac available, you can put this one into Target Disk Mode and use that Mac to boot off the iMac's internal drive. You can then configure display mirroring and remote control (VNC) so that the next time you boot the iMac (normally), you'll be able to better diagnose it

  • I did mean LVDS cable being faulty if someone pulls it improperly. Anyways could you expand the last paragraph you wrote. I can connect two iMacs using thunderbolt cable, how would I be able to configure display mirroring and remote control (VNC) Also what do you mean next time I boot the iMac I will be able to better diagnose it? Will it be automatically mirrored to external display?
    – metron
    Oct 6, 2020 at 10:18
  • 1
    Boot another Mac using the iMac's drives as the boot device via TDM. Make your changes (enable Mirroring, remote access, etc.) then boot the iMac normally. If the main screen doesn't work you can either see the screen via external monitor or you can remote into it. Yes, you can install Mac OS using TDM
    – Allan
    Oct 6, 2020 at 14:10
  • 1
    A broken LVDS cable is usually no video at all. You have to open it up to find out if someone attempted a repair so, again, you have to put hands on, but in my experience, very unlikely.
    – Allan
    Oct 6, 2020 at 14:14
  • 1
    You have to use an OS compatible to both the 2017 and the 2012. Since Catalina works on both, you should have no problems. macOS installs all drivers (kexts) necessary regardless of hardware. Windows installs drivers based on hardware, macOS doesn't have to. Windows "selects" which drivers to install because there is vastly much more hardware permutations than macOS.
    – Allan
    Oct 6, 2020 at 16:03
  • 1
    You should be fine!
    – Allan
    Oct 6, 2020 at 16:33

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .