So has there been any update to this thread? I have run into same problem with amp just got. replaced guitar input jack and hear nothing, no static, hum, buzz....plug mp3 player in the jack on the back and hear it fine through speakers. quick visual and nothing stands out but plan to bust out magifyer to look more closely at solder joints. just curious if anyone had the fix out there. just to clarify, all lights coming on, using known good cord/guitar as well. just nothing from amp when using guitar jack. Tried reset, nothing. Tuner does not recognize the guitar either if that helps. I am not using a board at the moment. Looking to buy one but wait and see if get working. thoughts?