I have an HP ENVY 17-j053ea which has suddenly decided to stop working. I get the charge socket light on but nothing else. I have tried holding the power button down for 30 seconds with no battery or charger connected. No joy. I have stripped the whole computer down and checked the operation of the power button itself and checked the ribbon to the mainboard. No signs of burnt out components anywhere. I the maintenance manual but no more detailed info. I'll check voltages on the power connector but I guess its dead. Anything else I might look at?