Hi,
I've got four boards, and one just stopped running. Pin 5 is not connected and showing 0.051V. I cannot measure a short on the output or any reason this should have stopped working. I swapped parts with another LM2674 and get the same result. The datasheet shows this pin can be left floating for "always on" operation. Is this true? Other areas to look? Everything on the board seems operable otherwise.