Screen/Charger/Computer/Dunno Exactly problem

Yeah, not exactly sure what the source of the problem is. Screen is definitely effected, computer seems to be, charger seems to have something to do with it. Here's a little story of the events I posted at another forum, hopefully someone can tell me WHATS UP:

So, whenever the night was when it was thundering around here(tuesday?) I unplugged the charger thing which charges my laptop directly like any other computer, I never use the batter, so that it wouldn't surge or whatever. When I did this the screen got really dark. It was still functioning, but you could just barely see stuff. After while the it just stopped functioning in even that state. So I tried to turn it off and turn it on several times, each time either the screen went really dark again or it just shut down after about one second into the loading process. After awhile I tried to turn it on with battery power, and it worked that way, but whenever I tried to put the charger back in so it could run off regular power, the screen went dark/it shut down again. So I used my computer like that for the past day or two. This morning, I turned it on on batter power, everything was cool, then suddenly on BATTER POWER the screen went dark. So I tried to turn it off and on, and now even on battery power the screen shuts down after the initial loading process.

Anyone know what might be wrong. Computer is a Dell Inspiron 1520 with Vista basic.