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iMac Start-Up Issues

My iMac will not properly start-up. It will cycle through the start up sequence for hours, and when it finally reaches the end, it will turn off and turn back on and start back from square one. Sometimes a power logo with an error message will come up and then do the same thing over again.

iMac 27", OS X 10.11

Posted on Mar 29, 2020 1:22 PM

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Posted on Mar 29, 2020 1:38 PM

PRAM reset, CMD+Option+p+r...


http://support.apple.com/kb/HT1379


In fact, do 3 in a row, takes a bit of time.


Intel-based Macs: Resetting the System Management Controller (SMC)...


http://support.apple.com/kb/HT3964


Safe Boot from the HD, (holding Shift key down at startup), does the problem occur in Safe Mode?

6 replies

iMac Start-Up Issues

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