I have the same configuration and problem.Some times the digital signal works again for a few weeks and then disappears and I have to reconnect the analog one.It is not a problem of mecanical connection. Thanks for any suggestion.George.
My PC or screen is suddenly not picking up the ditial signal through the cables only analogue. I have tried new cables but screen still says 'no signal'.
My scree is a Viewsonic VX912 and have a NVIDIA 6600gt Graphics card if that is what gives the output.