Dell Inspiron Display Issue

I have a Dell Inspiron 1520. The laptop display has suddenly become very dim. Here is the problem. When I switch on the computer, I see the Dell logo for a second or two, then I hear a sound near monitor and the display becomes extremely dim (I can barely see anything). If I connect this to a external monitor, the display seems to be fine. Could someone suggest possible solutions to this? I was looking at getting a replacement monitor from Dell itself. I wasnt sure if replacing the current monitor will solve the problem. Futher, I just noticed that as I turn on the laptop, the fan doesnt seem to run. Is this normal? Could the two issues be connected? Any comments and suggestions would be appreciated. Thanks.

sounds to me like the inverter needs replacing.. here's a link explaining how to test it. :- http://www.laptoprepair101.com/laptop/2009…rter-in-laptop/