Hmmm,

1. Did you install a new heatsink and fan that were approved for your new processor?

2. Is the CPU fan spinning when you power up?

3. Try disconnecting the HDD and CD/DVD drives and see if you can get into the BIOS

4. What lights come on?

5. What are the specifications for your hardware? especially the PSU.

6. What do you see on the screen when you try to boot?