1. does the script on the ID strip say 1x512?
or, 2x256?
2. We install lifetime warranty memory from any ofthe top companies.
3. There are only two slots in the MacBook. If you want to upgrade, suggest you get two 1GB strips, and pull, all the rest... It's the only way.
4. It must be faster than 1.5Ghz, cuz the slower MacBooks couldn't address over 1.5Gb of RAM.
5. Let a local Apple certified shop do the job to invoke the warranty, and you'll have some professionals who are on good terms with the Memory Corporations, and can be in your corner if the memory tanks!
Plus, whenever we take in a computer for any repair, we run the serial number and update if FREE, and check all the recalls, extended warranties, if any, with Apple!!!
Finally, when you open that unit, you really do need to be at an ESD static workstation!!! We get in units for repair all the time where the owner or their 'geek buddy' has toasted a $500.00 main logic board!
So, don't be STUPID, get some professional, guaranteed, memory and installation. Apple.com has lists of thousands of certified Apple Technicians. Yes, we'll even install YOUR memory strips, from a SEALED ENVELOPE!!!,but, we hope you'll buy good quality... bet you can guess why!