I'm trying to upgrade my MacBook's RAM to 8GB (2×4 GB), but somehow when I install the new cards I got the 3 beeps + 5 seconds pause. The 4GB cards were already working in another early 2011 MacBook.
The point being that, if I install the memory in a mid-2009 in a 2GB+4GB configuration, the Mac runs well. I have tried to switch cards and slots and it works, too.
Does anyone know what's happening?
Best Answer
3 beeps + 5s pause means your memory failed training. There are a LOT of reasons this happens. Let’s consider the most common.
First, let’s make sure your system supports 8 GB. According to Apple, the mid-2009 MacBook Pro does support up to 8 GB:
Now let’s consider a couple of possibilities: