Yup. The same thing happened to me in the last few days. Not only does the 65W adapter not work anymore, but the 90W adapter that I got as a spare (and have almost never used since I bought it almost a year ago) is intermittent. I seems to work sometimes but then the light turns off and it stops charging the laptop. Strangely, when the 90W adapter light is out, the adapter makes a faint beeping noise, about once a second. Most likely the adapter is bad and needs to be replaced. But I don't understand my the one that's basically brand new is not working for me. I'm waiting in queue for Dell chat and hopefully I'll get some answers soon. Good luck!
- dave

Me too it does the same thing, but I have a Inspiron 1520 with the 90W adapter et when I plug it, it makes some noise and the green is turn off.  And when I shake it and play with the cable, the green light turn on,it makes no more noise and it works ... until I deblug my power supply, when I plug it again, it's doing it again.

I found in other forums, the power supply is dead, call at Dell support and they will send you a new supply.

In my case, Dell not only replaced my power adapters (2) but they replaced the mother board too. This was after trying to run some diagnostics on it through online chat with Dell Support. Strange but true.

Thanks for all your replys everybody, they were very helpful. Unfortunately for me I needed access to my PC ASAP and I ended up buying one. On the plus side I found an OEM adaptor for $27 (new!) so it's not the end of the world. I was just surprised to see how quickly the original power supply failed - within 9 months of purchase.  The other thing that sort of surprises me is how much Dell charges for a new adaptor for those that do need to purchase a new one.

 

Thanks again!!