Macbook PRO 3BEEPS not starting up

You should expect 1 beep when you have removed both memory sticks - telling you that no memory is detected.
If you get 3 beeps, then memory is detected, but doesn't pass the power-on self test.
Have you tried swapping the sticks between the slots?
Also, try just one stick at a time - booting to check for a good boot with only one stick. If you get a good boot, then try the other stick, again only in that same slot. If you can boot with _either_ stick in one slot, then add the second stick. If you do get a good boot with only one slot, you can try a variety of combinations of the memory that you have now, testing to see if you have a failed memory slot. You may find out that one stick is bad (mark it, then test again just to make sure.)
You _might_ find that both sticks work after reseating the sticks a few times - which is a pretty normal result - proper seating can sometimes be the permanent fix.

50L said:

or is it possible to but only 1 ram card of 4GB and have same result as 2X2GB

Click to expand...

Yes a 4GB stick should work. Maybe even an 8GB stick depending on model.


Barney