If you have greenlight on battery, and no boot, then you can try the battery trick.
you must unplug the ac power convertor. Unplug it so it makes two parts, and unplug it from the wall. Set it aside.
Take your laptop, and take the battery out. Then press and hold the power button for 30 seconds.
Now put it all back together, and try it. If it works, it works. If it doesn't you must take it to a technician!