Hi, Please excuse me for my English Please help. I have 3 y.o. 27 in IMac (mid 2011) model. Spontaneously it is started to reboot into white\gray screen with purple stripes, then it goes to constant reboot cycle. After I shut it down and wait it might boot normal or might not and still give me these stripes. Brought it to authorized store and it booted just fine in the store. They said that I had uncertified memory installed and it is true, but these memory was installed for 2 years now and never created an issue. They have removed it and said that issue is resolved and Dx test was fine. When I brought it home ( no uncertified memory) issue still continuos . Please help.