My father has a 27" iMac bought in 2011, his main desktop
It's a 27 inch model with a 3.4GHz i7, 8GB Ram, 2TB HDD and 2GB AMD HD6970m GPU.
2 days ago when turned on (he uses Windows 7 on it a lot for Microsoft Access, the default OS) once the system got past the grey apple boot screen it came up with blue/black vertical lines across the screen. The rest of the system seems to function fine but nothing can be seen.
I know the 6970m is well known for failing and it looks like a GPU failure to me.
However just to be sure, I thought I'd check with people here. There's some things that confuse me if this is the case:
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Assuming it is the GPU, what are our options? I know the system recently fell into the vintage category. I am pretty handy with Mac repairs. I've taken apart iBooks and Power Mac's before but I'd rather avoid opening up this more valuable piece of kit if possible. I know people have had results with "baking" the GPU in the oven. Ordering a new GPU is pricy, but that's not a big problem if it will work. But honestly we're happy to pay a few 100 euro to get it fixed professionally.
It's a 27 inch model with a 3.4GHz i7, 8GB Ram, 2TB HDD and 2GB AMD HD6970m GPU.
2 days ago when turned on (he uses Windows 7 on it a lot for Microsoft Access, the default OS) once the system got past the grey apple boot screen it came up with blue/black vertical lines across the screen. The rest of the system seems to function fine but nothing can be seen.
I know the 6970m is well known for failing and it looks like a GPU failure to me.
However just to be sure, I thought I'd check with people here. There's some things that confuse me if this is the case:
- Booting Windows or MacOS or Mac Recovery results in either the blue bars (windows), an instant restart (MacOS) or indefinite hanging after bar loads 1/4 of the way (recovery/usb boot).
- When I boot with an external monitor connected, I can use Windows 7 in safe mode with no problems! This is the main reason I'm unsure if it's 100% the GPU. Should this really be possible? (I can also get a little further with the external monitor in a normal windows boot before I get the lines)
- The Mac boot selection screen (alt key on startup) displays fine on the built in display and external display.
-------
Assuming it is the GPU, what are our options? I know the system recently fell into the vintage category. I am pretty handy with Mac repairs. I've taken apart iBooks and Power Mac's before but I'd rather avoid opening up this more valuable piece of kit if possible. I know people have had results with "baking" the GPU in the oven. Ordering a new GPU is pricy, but that's not a big problem if it will work. But honestly we're happy to pay a few 100 euro to get it fixed professionally.
