Cannot start up laptop after overnight disconnection. If I leave computer shut down on AC power overnight, laptop starts up fine. Have tried all methods e.g.removal of battery and button pressed down for 30 seconds etc. but still nothing happens. However, LED lights show but if button is depressed, one of the LED lights goes out! If I leave the computer on AC power for say 20 minutes, the laptop button does work but I think the problem may get worse over time.