Chosen Solution
I just got a new 2x4GB ram upgrade for my macbook pro. After I switched the old ones for the new ones, I turn it on and the machine starts beeping. I figured was a problem with the ram. I thought the new memory was incompatible with my macbook. So I switched back to the original ones, and there comes the beep again. So I took the bottom memory stick off and leave it with the upper one only. The machine turns on fine. I figured the bottom slot was damaged or something like that. But then I switched the ram, I put the one stick on the bottom and leave the one on the top empty, and it turned on just fine. So everything works fine as long I use only one slot, either one, doesnt matter.
Try resetting the PRAM when you change the RAM and see if the problem persists. Here’s how to reset your PRAM: Shut down your machine. Yes, all the way down, not sleep or logging out. Press the power button and then press command-option-p-r. … Hold those keys down until your Mac reboots again and you here the startup chime. Let go of the keys and let your Mac reboot normally.
