Recently I've had a problem with getting my laptop to start up again after being in sleep/hibernation mode. After pressing the power button, the display lights come on and the fan starts to run for about a second and then stops. The screen stays black and the computer itself starts to make a strange bleep/click noise repeatedly. The display light stays on during this process. Normally it takes me about a dozen tries of turning it off and on before it starts up again, but I haven't had such luck tonight. I've reseated my battery, tried several hard reboots, etc. Nothing.
The battery was full and the power cord is almost always plugged in. I had left my laptop on (with the screen locked) and the lid up when I left the house this afternoon, and it's been like this since I've been home again.