Hello all First time Marshall owner. I just purchased a DSL40CR second hand. I played it in front of the seller and everything was working and sounded great. I played it a bit more downstairs before moving it to its new home and no issues. I planned on splitting my guitar out to that amp and my Fender Hot Rod Deluxe. I used my Fender PT100 tuner with the HRD in Output 1 and the DSL in Output two so that stomping the tuner would switch between both amps or one. It worked until I hit my Boss RC1 looper from my pedal chain and ever since my DSL has no sound. I have plugged my guitar directly into the amp, turned up the gains/volumes on both channels and both masters, toggled between channels, toggled between masters and still nothing. It turns on, all the lights work and the channels clearly change. The tubes are glowing so I assume they're fine and the amp is still fairly new. When the amp turns on, there is literally no sound coming out at all, just pure silence. What could be causing this and what have I missed? Do I need to take this to a repair shop or is there something simple?