M1330 Motherboard and CPU Problems

I have an M1330 Laptop that began to have problems starting last February.  The computer would star tto freeze up and needed to be rebooted frequently.  In early April is stopped working completely.  After troubleshooting came to the conclusion that the motherboard bus had fried and I purchased a new replacement motherboard and installed using the downloaded manual instructions from Dell.  The laptop would not start up after the replacement.  Would get to the point of startup just before the hard drive should initiate, but no farther.  I then purchased a new CPU thinking it may have been fried with the motherboard, but still does not start up.  Was a great little laptop until the problems started in February.  Anybody have any suggestions for resolving the problems?