Sometimes when my laptop goes into sleep mode, the fans turn on full blast, and it won't wake up. This happens when the laptop is plugged into power (I haven't tested while on battery) and is open. The keyboard lights are on, as are the power button and trackpad lights. Pressing keys, touching the trackpad and pressing the power button have no effect (holding the power button down long enough will shut off the computer, though). fn-F6 does not turn on the screen. Pressing the trackpad disable button does not seem to have any effect, so it seems like it is more than just the screen being off. However, fn-F9 will turn on and off the keyboard lights. Closing the lid will cause the lights on the back of the lid to turn off, but does not cause the fans to stop.
Any idea what might be causing this, or how I can fix it? I've run out of ideas.