Chosen Solution
My iMac screen suddenly started showing stripes only. It starts up normally, but I can’t see anything, Everything works fine but the screen itself. All it’s displaying is just stripes vertical and horizontal. The iMac never fell, nothing ever hit it. I napped leaving music on the computer, after waking up I found the screen totally messed up. I wonder if I over used it. I tried everything I can rebooting and so on, nothing works. Now I have no idea what to do! I’m a graphic designer and I work with it a lot. It never showed any malfunction for two years until now, I also have no warranty left and I don’t trust third parties at all here in Morocco, most are scams. Hope someone can help me do something . Update (05/27/2016) hey am back i will try to connect the iMac to an external monitor , if the gpu is dammaged am basically screwed … thank you guys for your answers i really apreciate it , the mac was so expencive to buy and after only a year of work this happens to it , i dont do any heavy work on it and i dont overheat it at its always cool and chill where i live not too hot because i live next to the sea, i really hope its not the gpu
This is usually a GPU failure (graphic processing unit). This is the first one I’ve seen on this year model. To be sure hook it up to an external monitor and see if the distortion is also on the external. It can be replaced or repaired usually by heat treating or recalling the solder on the chip. I’ll do some research and expand my answer in just a bit. The first thing to do is find out your EXACT machine. Get the serial number off the bottom of the stand and plug it in to this link, then tell us your results: http://www.everymac.com/ultimate-mac-loo… If the EMC number you gave is correct it is one of three machines: The GPUs are all the same: GeForce GTX 775M Unfortunately it appears it is no longer on a separate GPU daughterboard but now integrated into the logic board. See it here on step #6, second photo: iMac Intel 27" EMC 2639 Teardown Your options are to replace the logic board or find a really good tech and let him try reworking the chip with a hot air re-work station. I found both in China and the prices are good: http://www.ebay.com/itm/Permanant-Engine… http://www.ebay.com/itm/Repair-service-f…
