Chosen Solution
That should be fine. Make sure the 2GB stick is the exact same specs as the original RAM. Then Go to the “About this Mac” on your machine and go to more info and make sure your machine sees the 2GB stick.
I was hoping that Majestys’ answer would work, but alas. I have found on some of these “bad port machines” that a lesser RAM chip will work when the higher ones will not. I’ve been able to install 512 k chips in slots that no longer will take the 1 GB chips and its worked fine. Other just won’t take anything. It’s worth a try if you have the old original chip lying around.