Troubleshooting shorts or opens on Laptop

Most common cause: shorted/open MOSFET. Check the FDS6679.

Blue ring will not light up with known good power supply and shuts off power supply. Unplug power supply from wall to reset.

With open AO4407, laptop still run off AC but not battery since no current is going to the battery charging section.

With shorted FDS6679, it shuts down power supply to protect it. unplug power supply from wall to reset.