There are no audio cable connected, when AC power is turned on it starts with green LED and hum – I would expect red LED and no hum.
There are GND connection from audio connector to PCB2 connector P4-3.
Apprently is picks up noise internally, but where from?
Any idea what that could be?
Okay, to finish up my own thread 🙂 my conclusion is now that there did not exist a proper connection between aluminium part and amplifier despite being screwed together. I noticed that the screws are some kind of black CED coated, and by working the screws back and forth several times the hum disappeared and the speaker now works as it should.
Basically, when you are in LINE IN mode, you NEED to have everything terminated properly, even if there is no RCA plugged in.
For my case, by BL6000 needs to be have Line-in RCA plugged in to the source using a cable, before everything is silent. If you don’t want to plug anything in, you need to short the input via a terminating plug.