I was recently asked to look a a Dell Inspiron 6000 which refused to power up. If the battery was charged in another system it ran fine from the battery. After a quick check on the internet it appears that the DC power jack is a common fault with these laptops. I purchased a replacement jack and set about replacing it. Dell provide a service manual for all their systems including the 6000 and it has details on how to strip down the laptop and rebuild it.