While showing a presentation a few days ago my laptop went into hibernating and shut down. AC plugged in. When attempted to power back on nothing happened. LED lights on front panel blink but power LED does not. My laptop is HP Pavillion dv5000.
Probably the power (AC) adapter is dead. I think your power adapter died while the laptop was showing a presentation. Without AC power the laptop was working until the battery charge went down to zero and then it hibernated. Now, the front LED flashes but the laptop will not start because the battery is discharged. The power LED will not light up because the power adapter is dead. That’s my guess.
Before you purchase a new power adapter, I would suggest testing the old one with a voltmeter. If the old adapter is OK you may have a problem with the motherboard.