So I have a Powerbook G4 1.5GHz with 512MB RAM, and I've been trying to install 1GB RAM that I ordered from OWC, with no success. I've tried putting it in by itself, in both slots, and it gives me a single beep and nothing else, so it doesn't recognize the RAM. When I try it with the 512MB stick that I already have, the computer turns on, but it still recognizes the second RAM slot as empty. I tried switching which slot they are in, and it still only recognizes 512MB. I've also tried resetting the NVRAM and PMU, still with no success. I exchanged the RAM, and the new one came in the mail today, and I've tried all of the aforementioned things, and it is still not working. Do I just need to keep exchanging the RAM until I find one that my PB "likes," or is there anything I can try?