OK the three Beeps are a RAM issue, as you already know. You are correct, and did the right thing.
Now you need to test if a slot has gone bad or partially bad.
Remove the RAM, use canned air and blow the slot out.
Take one stick only, try it in both slots to check out both the RAM and the slot.
Now you have known good or bad sticks or known bad slot.
If the slot, try loosening the screws that hold the slot in place - crazy, I know but it can work.
Test again.
If RAM is bad, trash it.
If slot is bad, use the screw solution or sometimes it will take a lessor stick (if you have one).
If not live with one stick, the highest your machine will take. ( a 4MB)
RAM Type: PC3-8500 DDR3 Min. RAM Speed: 1066 MHz
Standard RAM: 4 GB Maximum RAM: 8 GB
+
+
In the past I have found, after many days of trail and error, that the RAM may have had ESD damage and cause erratic behavior. Work one day and not the next. Unless you are a Professional the time spent discovering this is nauseating. To test it you need a program like Atomic by Micromat: http://www.micromat.com/store#atomic
OK the three Beeps are a RAM issue. You are correct, and did the right thing.
Now you need to test if a slot has gone bad or partially bad.
Remove the RAM, use canoe air and blow it out.
Take one stick only, try it in both slots to check out both the RAM and the slot.
Now you have know good or bad sticks or known bad slot.
If the slot, try loosening the screws that hold the slot in place - crazy, I know but it can work.
Test again.
If RAM is bad, trash it.
If slot is bad, use the screw solution or sometimes it will take a lessor stick (if you have one).
If not live with one stick, the highest your machine will take.