I hope the hangovers have subsided

I got a runflat warning last night for the passenger rear ,
I connected my digital compressor to take a pressure reading but i'm not getting any air through the valve ,
I checked the operation manually pushing the pin in the valve but still nothing would come out,
Is their a problem with the valve or is this a characteristic of runflats with a puncture ???,
The tyre looks and feels ok but i cant say for sure what pressure its holding,
Thanks and all the best,
Bob.