GFI test-reset

[DandD]

Lights and plug over bath sink not working.
No breakers thrown.
Black "test" switch will not depress Red "reset" will. Is switch blown?
Also have little info in box on what breaker works these connections.
How is that searched down?

Thanks!
D&D

[HayZee518]

seems like the internal plastic links to the trip circuit are broken. only way would be to remove the outlet "hot" and test with a meter on the upper two screws and have an assistant start flipping breakers one at a time until the circuit is found. OR shut off the main and remove the outlet, then tape up the black wire(s) and turn on the main and again using a test light or meter shut off breakers one at a time until the circuit is found. Leave the breaker off and replace the outlet.