Answer to "System not booting, no boot chime, sleep light solid on"This time, the charger was the problem. I guess it has an overheating protection, since it works again after being unplugged for about an hour. Also, this seems to happen when the computer is asleep and the battery runs empty. Perhaps it somehow draws full power during sleep? ..last time it was nvidia chip overheating. Got them to replace the motherboard on the extended warranty.