this is common problem with dell laptops where they have problems with recognising the charger.

www.youtube.com/watch?v=p5s9guCcRmw
How to repair the Dell power supply problem , where the computer no longer charges the battery or recogises the power supply .... Main problem is the silicon by the adaptor right at the back of the computer hardens and cracks thus braking the Red Data ...

jack380.wordpress.com/2009/03/06/how-to-solve-the-problem-de...
I have brand new Inspiron 1520. Battery fully charged, when I unplug the charger from the wall, but let the plug in the Inspiron for a while (let’s say a night), when I startup my computer, I get the message "The AC power adapter type cannot be d ...