When my laptop is turned on, the startup chimes normally, but nothing else happens...no screen display, the hard disk doesn't start powerup...nothing just the faint sound of the fan and power. What to do? I have tried to startup by cd, zapping the pram??? What else should I do? I do have access to another identical laptop if that helps in swapping, etc...but is it ok to pop open a laptop? I have done it many times with desktops, but only added memory etc with laptops...

Short one here - so get back to me about it: Try replacing the battery from the other identical model - you don't need to open it - just pop-open the left side and slide it out =) tell us if changes anything cheers cw

Have you reset the PMU? (Power Manager Unit), its in different plavces on different models, see your owners manual or the back panel of the PB (You did keep the manual right? ;-> )if not looks here: http://docs.info.apple.com/article.html?artnum=58416 If this fails, try taking the Battery(s) out and running on power alone, sometimes PowerBooks get their Energy Saver prefs corrupted and the machine turns on thinking it should be in Sleep. Sometimes just hitting the space bar on the keyboard helps, then change the Energy Saver control panel (OS 9) or System Preferances>Energy Saver in OSX