Here’s a simple trick you can try if your computer won’t power on at all.  No sign of life when the power button is pressed.  Have this Dell Latitude D630 that has been work fine with no issues what so ever.  But today when try to turn it on none of the lights will come on, it’s like there’s no power connected to the laptop. 


 I checked the AC adapter and the light indicator is green meaning it’s getting power from the wall outlet.  I then checked the AC adapter with a multimeter and it’s putting out the correct voltage.  The battery it’s also showing it’s fully charged.   Removed hard drive, DVD drive, PC Cards, memory, and battery but the system still will not power on with just the AC adapter.  At this point I thought it’s got to be a bad systemboard.  But wait,  here’s what I did to get it to power back on again.   Since the only thing attached to the laptop is the AC adapter I unplugged that as well.  Then press and held the power button for like 20secs, plugged the AC adapter back and the laptop is alive again.  All the lights came on and it booted to the Dell logo screen.  Put everything back together and it was back in business.