Ran Down (1st) ES9038PRO DAC main cause of the NLOCK (~ 4 months of troubleshooting showed me, it was not the dedicated TCXO clock module):

    This single loose solder ball (could have fallen inside the enclosure at any point) might explain all the problems I had with getting the DAC to lock on to any audio signal. It would be a great job if it wraps up the issues. Stay tuned to find out if I was right! […]