my 27-inch, Mid 2011 mac screen keeps going black so i push power button and it sounds like it closes down but then i push it again the will be normal! is there something wrong with my mac?
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It's possible that the display isn't working properly. First, reset the PRAM > http://support.apple.com/kb/HT1379 Then, reset the SMC > http://support.apple.com/kb/HT3964
If you can, I recommend you to connect an external display to your iMac and check that it's working correctly
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