HP dv7-2173cl issue when upgrading CPU, checksum error

Hello,

I have an HP Pavilion dv7-2173cl... i recently installed/upgraded a new processor from a Intel Core 2 Duo 2.0Ghz P7350 to a Intel Core 2 Duo Xtreme 3.06 Ghz X9100 . I assembled the latop back together and boot it up. It stops and it says:

"Checksum Error"

press"F1" to load Cmos default value

Press "F10" to BIOS setup options

I have tried pressing both of buttons, and nothing wroks. It wont even restart after pressing ctrl+alt+del. I cant get into Bios either upon booting up. I have tried to reset the BIOS by switching the jumper pin, but there is no pin to be found. I have also removed the CMOS battery for 10sec+, but still getting same issue.

I then proceeded to call HP. HP stated that I am getting this msg becuase the processor is not compatible with the motherboard I have and were very insistant on me buying a new motherboard. Is this true? I have bought the upgraded processor on ebay and ran through other forums where they basically state that the CPU is exchangable with my current laptops motherboard. Any help appreciated.

Thanks

Yeah, I actually installed back the old CPU booted back to the OS, downloaded the correct BIOS, shutdown, put back in the new processor, and was able to flash the BIOS to the correc CPU... laptop is much faster now... i just cant believe HP would lie and tell me it cant be done and that I have to get a whole new motherboard to upgrade to that processor... screw them!