dell inspiron 6000 power problem

this laptop will not charge from the adaptor, have tested the adaptor it is working. The computer will run on battery but that is nearly dead, I am not happy as I am one of unfortunates with a faulty battery before, the computer closed down completely then when restarted would only function on battery. I think this seems to be a common problem with the inspiron I think some thing must have burnt out inside? the jack has always seemed rather fragile any advice please