If the beeping with the power light is like three short beeps and then about a second before the pattern repeats, then you have bad RAM, or less likely, a bad MLB.

If the unit is under warranty still, take it in. If not, you can remove the bottom case and test each RAM module, individually, in each memory bank to try and isolate which is the bad module or memory bank. The good news here, is that if the unit is not under warranty, the odds of it being your RAM are considerably more likely.