help, my laptop won’t boot!!

hi,

i just bought a used dell laptop CPi model, and it worked ok for the first few weeks. then it started running intermittently rough. then last night, it would not boot. it would not even get to the POST process. i see the LED lights go on, then 3 seconds later the machine shuts off. i tested the power supply and it works fine. i’m thinking it could be the bios, or worse perhaps the processor is spent. anyone have any experience with this? any advice would be totally appreciated.

thanks!!
joe