iphone 5s update 12.5.4 = suddenly a fast busy signal with all outgoing call attempts. Online search came up with ...
"The fast busy is called "reorder" in telephone parlance, and it means that the phone could not connect to the network past the switch that took the call attempt. Your call got as far as the switch, but the switch itself could not connect you further. "
"A fast busy used to be a pretty good indicator that authentication had failed. Authentication was what kept phones from being cloned. That's rare now, though. I have heard of it happening occaisionally. Sadly, not all of the folks at tech support are familiar with the process of resetting an A-Key. "
How do I get this fixed? Guy at Verizon store was stumped. Apple store only gave me an appointment. Trying Verizon tech support chat on phone failed. Thanks - Catherine