I need an Audio Detective

Hello AG I have a unique situation with my audio system that I have no answer for. Here’s the deal. I was playing my Magnum Dynalab tuner and noticed my Denafrips Terminator 2 DAC standby light was not on. The power cord had come loose from the back so I snugged it up and the light came on. For whatever reason I hit the on button on the DAC and when I did it crushed the signal on my tuner. I cut DAC off and signal came back. I tried another tuner same result. Any ideas as to what is going on?