14 Replies Latest reply: Feb 10, 2013 10:53 AM by steve359
Andres_Santacruz Level 1 Level 1 (0 points)

I have a late 2011 Macbook Pro 15 inches, i recently upgraded the RAM from Crucial 8gb (4gbx2) to Crucial 16gb (8gbx2).  I have done thies before, was er careful, and had antistatic clip, clean work surface, etc. When trying to turn the computer on again, i hear 3 slow beeps, repeated three different times, and the computer does not turn on.  I have been looking around for solutions.


  I have already swapped the memory modules, cleaned them, dusted the whole computer with air can, put the old ram in and still have the 3 beep problem.  It no longer works even with the old ram.  The computer was working perfectly fine before this.


  Am i missin a step?  I saw in a video on youtube that i have to reset the RAM with Alt+P+R+Power button, but nothing happens.


  Please help, i am self employed and my Mac Book Pro is the computer i work with!


  I have Lion operating system, everything updated very recently.  Stock 512 gb hard drive.

MacBook Pro