I have a MacBook Pro (2.16 GHz Intel Core Duo) that went in for repair and the technician charged me an exorbitant amount to replace the MLB (Main Logic Board). Is there anyway I can check or verify whether he really did replace the MLB ? I did some research on the internet and found an old forum posting with the following information:- When you have the original logic board, you can go to apple menu, about this mac (system profiler) and get the serial no. When the logic board is replaced, it will not show the serial number. In older macs it used be some dummy number 12345... and in my MacBook Pro it says "SystemSerialNumb" (it becomes a pain when u call AppleCare because after the logic board replacement u have to remove the battery to read the original serial no) After the repair my machine is working, however a proper serial number appears clearly under the system profiler which you access from under the Apple pull down menu in the top left corner, when you choose "More Info..." in the "About this Mac" window. I checked this number against the serial number that is physically imprinted on the back of the machine under the battery - you have to remove the battery pack to see it. The number on the back of the machine is exactly the same ! I have an uncomfortable feeling that the technician is being dishonest with me and may not have replaced the MLB in my machine. Can someone who is technically well versed with such stuff please help me ? The Apple technician is pushing for payment and I need help fast otherwise I will be left with no option but to pay him for something that was not even replaced or installed in my machine.