hi, ive got a texas intruments extensa 575cd. when i hit the power switch, the speakers make a sound like theyre coming on, but nothing else powers up. no screen, hard drive, nothing. ive tried the battery (which is good), the ac power supply, etc. someone told me to replace the cpu (p100) so i slapped a p150 in (it would be underclocked but what the heck) and it does the exact same thing now. so i know the cpu isnt bad . can you help me out? thanks.