Sanwu SW-HF05 - TDA 7498 not working

Hi all,

I am new to this board and this is my first entry. I spent some of my free time with vintage audio and Hifi years ago, now my kids have grown older I may restart my hobby. I rediscovered an amplifier board I bought of Amazon some years ago, which I never used. It's a Sanwu SW-HF05 with TDA 7498 chip. It's still brand new. Unfortunately I cannot get it to work. I connected the speakers and Line in and a 19 V power adaptor. A red LED is lighting up but thats it, there is no sound or any other sign of function.

I tried the cinch cable and speaker wiring with a different amplifier and it works. What am I doing wrong? Somehow it seems like the Sanwu is in Standby mode? Can this be?

Best Regards