I have a late 2009 27" iMac which has served my well for many years. Unfortunately, it seems the graphics card is broken. Trying to boot normally, I just get the grey screen of death after the initial chime and Apple logo. First of all I tried all the usual resets, including:
- Safe boot
- Boot into recovery (including Internet Recovery)
- Re-install OS from OS X DVD
- Clear NVRAM
- Reset SMC
- Booting into recovery mode works (CMD+R) with mayor graphical glitches.
- Trying to run the Apple Hardware test (D) results in the same grey screen of death as the on normal boot.
Thanks to the tips from Boot hangs on grey screen (even when booting from USB drive with fresh OS X install) I de-activated the graphics card by booting into single user mode
CMD+S on boot and moving the driver files:
/sbin/fsck -fy / /sbin/mount -uw / mkdir /dsle cd /dsle mv /System/Library/Extensions/ATI* . mv /System/Library/Extensions/AMD* . touch /System/Library/Extensions exit
After this OS X normally boots up into OS X again, so I guess the graphics card is broken.
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Graphics/Display the graphics card is still shown correctly:
ATI Radeon HD 4850: Chipset Model: ATI Radeon HD 4850 Type: GPU Bus: PCIe PCIe Lane Width: x16 VRAM (Total): 512 MB Vendor: ATI (0x1002) Device ID: 0x944a Revision ID: 0x0000 ROM Revision: 113-B9110C-425 EFI Driver Version: 01.00.383 Displays: Display: Resolution: 2560 x 1440 Pixel Depth: 32-Bit Color (ARGB8888) Main Display: Yes Mirror: Off Online: Yes Display Connector:
But even with the graphics card de-activated, there are graphic glitches.
Dose this mean the OS is still running of the dedicated graphics card? Or dose this mean the error is somewhere else?