Laptops blinks light only

with the laptop start with pulling the hard drive if the hard drive fails sometime it can pull more power then the laptop mb can give out. also check that ram is locked in. on laptops check that the power plug not broken if it is it may have shorted the system board out. check the ac brick for broken wires and with a meter check it output to the one stamped on in. google the model of the laptop see if there any recalls on the system board or class actions. some dells had reclalled system boards. few years back bad nvidia chips got into laptop system boards.