> Is there anyway other than replacing it to test a power supply?
I'm far from expert, but the only way of which I'm aware is to take your Mac to either a "Genius Bar" or authorized Mac service center, both of which have access to tools to which we mere mortals do not.
> is the best way to determine what to buy to replace the power supply opening it up & looking for specs on power supply?
or perusing the apple site or another way?
Before going the route you're envisioning I suggest that you do some research to determine whether your power supply is user serviceable.
