If you have been setting up for digital modes and suddenly loose headphone audio out of your Flex 1500,   be sure to check your Windows default sound card settings.    Maybe you accedentally set either the Flex Sound drivers to your Windows Sounds playback or record or both.   The Windows default sounds should be set to your computer sound card,  not any of the Virtual Lines or Flex Radio drivers..    

Dudley

WA5QPZ

FlexRadio Support