Serial number after repair?

Question

My 20"G5 iMac iSight was repaired this week under warranty. The failure came without warning but everthing is working now as before.
However, now the System Profiler does not show a serial number. I have also run the hardware tests on Disk 1 for the first time. Everthing is OK and there is a logic board serial number with a different number of characters.
Is the iMac serial number is still the original one on the foot (base)?
Is it possible to get that number to display again on the System Profiler?
20" G5 iMac iSight   Mac OS X (10.4.7)   new logic board

Answer 1

Hello,
I have a little trick for you below. But, first I'll explain how this feature works and why it doesn't.
The serial number you were seeing in the System Profiler is written into a chip on the logic board.
But, when they refurbish a logic board, they clear out this serial number. Since they have no way of knowing which system it's going to be installed in next, they do not re-program another number into the logic board.
So, when you get your refurbished logic-board installed, that location that contains the serial number is cleared.
Apple will often reprogram the number into the logic board on complete systems that they refurbish. But, it is not common for them to do it on the individual logic-boards.
Unfortunately, the only way to get it to display in system profiler again, is to re-program that serial number back into the logic board. And, Apple is the only one with that tool.
But, you can continue to use the serial number that is printed on the foot of your computer for all warranty related items. That number is still your "official" serial number. So, the number you use has not changed. It is just not visible in your System Profiler.
Now, there is a little trick to make your serial number display in the "About this Mac" window.
You can read about that here:
http://discussions.apple.com/thread.jspa?messageID=1511437#1511437
I hope this helps.