1- If you left it for 2hrs on only battery then you need to recharge the battery.
2- get spare power lead from wall to power supply test it,
3- could be your power supply if faulty. Ot
4- connector socket on laptop have overheated.
Advice: never place your laptop onto pillow/ quilt/Blanche etc… this will block cooling fan then overheat can even melt m/board, always gap beneath it IT IS MUST