The pictures above show it next to the track pad for size. The little black arm that sticks out from the top is sprung. Not 100% sure it fell off this laptop (as I have never seen it attached) but seems the most likely explanation. The laptop appears to be working fine by the way so not mission critical.
Does anyone know what it is and if / how I should replace it?
PS. the laptop did take a knock on bottom right hard corner and got bent out of shape so that there is now a small gap in that corner (see below). Not sure if this is related but thought I would mention it in case it helps with the sleuthing!
Bonus question: can you buy a replacement case? I couldn’t see one in the marketplace. Will most likely wait until this one has taken a few more knocks but would be good to know for the future.
Now with the Battery still disconnected and the RTC Coin Cell still removed, plug your Power Adapter back into the laptop. At this point, you should see the LEDs on the left and right sides of the Mainboard start to blink red. This confirms that the board is powered on and in a reset state.
I decided to proceed anyway and see what happened. It did turn on and all is well.