Chosen Solution
The computer will boot. To the user selection page. It displays vertical alternating blue/light blue bars. After entering password it begins to load, then goes to a solid crisp grey screen. Then it shuts off or reboots to same user screen. This had been an intermittent problem until now. Apple says they don’t repair “vintage machines” but says it needs a new logic board. Can this logic board be repaired? Update (11/06/2017) This is a late 2011 MB Pro. I’ve tried plugging it into an external monitor and this happens: On the computers screen the same vertical bars and when I type in login info the screen goes grey but has double images. The loading bar continues to the point where screen goes black then comes back on with the proper and clear background image and begins to load programs. This is when the second monitor detects a signal and shows the same thing. I got as far having everything load then closed a window then the computer just shut down. I don’t get this far without plugging in the external monitor.
The 17" models are still highly sought after so its worth repairing! Even a Core 2 Duo system. Let’s see if we can localize what part/s need replacing here. Are you able to boot up holding the T key at the startup bong? You should see a floating FireWire symbol on the screen do you see it at all? If you do lets try plugging in an external display does the that look good?
Got much the same problem with mine, except mine has pink and white bars, it was fixed by IT Online in Melbourne, Australia last year for over $600 and had the mother board replaced, lasted a day or so then blew up. They repaired it again under warranty and it lasted past the warranty expiry date then blew up again! Is there anyone competent out there who can fix these things properly?
Try removing the logic board and remove the heatsink, heat the GPU with hairdryer for 5-6 minutes. Reassemble and try turning on the computer. If it works and I suppose it’ll work, then it means the problem is the GPU.
