Screws on bottom case coming loose

[MNtinkerer]

I noticed that the corner screw next to the barrel charger socket had worked loose.

Trying to screw it back in revealed that the female thread had clearly broken.

Can anyone suggest what I should do and what the consequences might be of not repairing it?

By "female thread had clearly broken" do you mean it is stripped completely or stripped until it isn't holding the screw tight? If there are still some threading there are thread locking compounds that can keep the screw in place or nearly weld them in place. Purchase the screw replacement kit from the Pine64 store to ensure maximum contact and use a thread locker. In most auto parts stores in the United States and Canada there is a brand called Locktite and their Blue compound is for thread locking. Their Red compound will make removing the screw nearly impossible. Be mindful that Locktite makes a lot of compounds, these two are the most common so take care to read the directions.

My understanding is that the screw mentioned, and it's twin on the other side are critical for helping keep the case together with the lid when opening and closing so not doing anything is not good.