I have a P3/1GHz Inspiron 8000 with a bad motherboard.  I need to identify the part # for the motherboard so that I can replace it.  I removed the motherboard, but I do not see an easily identifiable part # on it.  How do I determine which motheboard I have?  The motherboard had been previously replaced by Dell, and is different than the one that originally shipped with the computer.  As well, where's the best place to get a replacement?