I'm using a dell inspiron 1520 laptop with windows xp. Recently, I was working on my computer normally when it decided to go into standby mode by itself. The laptop was plugged into an AC outlet so it wasn't the battery. Also,when I re-login, the laptop usually lasts about 5-10 minutes before it goes back into standby mode on its own. There are also periods of time where the laptop can run fine for hours at a time. I've switched all of the power options to never for standby mode but I still experienced the same problem. I don't think its an overheating problem either because the fan seems to be working and it does not feel that hot. Also, sometimes the computer comes out of standby mode and I can here windows working in the background but the monitor remains black. Usually, the monitor remains black in these cases for about 3 minutes before it randomly comes on and allows me to see the usual windows background. Any help would be greatly appreciated.