I have a hp laptop (don't know the model). When i was moving the laptop, it was always shutting down. Last night, it shut down as always, but it doesn't start. One light is on but no fan and nothing else.
Remove main battery, unplug the CMOS battery from the motherboard, hold in the power button for 30 seconds. Without the batteries connected, plug in wall power and see if it turns on. If not, chances are good the motherboard is bad. You can also try without the drive and RAM, if motherboard is OK it would give you error beeps or blinks with RAM removed.