I have a 3-4 yo Samsung laptop. Had a Teams call earlier and when I clicked Join, Teams appeared to lockup. In my efforts to open Task Manager to close out of Teams, the entire screen went black. I can see (and move) my mouse cursor but that is it cant force boot (Ctl+Alt+Del) and the laptop does not have a traditional on/off button.

WTH do I do here?

Plug in an external monitor.
Not sure how you wake machine up but typically holding power for 15 second forces complete power down.
I have had to open my dell and disconnect battery to recover once