The steps did not work.
I did the steps shown above but my iMac system will not turn on still. All I can hear is the fan faintly blowing.
If your Mac still won't start up after you've tried each of these steps, visit an Apple Store or Apple Authorized Service Provider for further diagnosis. If you plan to visit an Apple Retail Store, make a reservation at the Genius Bar, if available in your country or region. Diagnostic fees may apply for issues not covered under warranty or AppleCare Protection Plan (APP).
