Thomann DP-28 Plus

I have several problems. I hope I'm just unlucky (I've open a ticket for a replacement).

- Center keys don't work at all (tried different instruments, with or without pedal, unplug-plug AC, etc...). Probably just a disconnected cable inside the keyboard, but it's problematic.

- Without playing any key, I can hear sizzling, a "buzz" sound. It's not very perceptible with speakers but very annoying with headphones (tried with T-bone and Focal headphones). It sounds like a very cheap DAC (even my nephew's 50€ keyboard don't make that kind of "buzz").

- If I turn the Lid to "Full Open" I have a strange windy noise.

- If I turn off the Hammer Noise (which is actually unnatural), I still have the same hammer noise as if it is on "Level 1".

That's just what I've noticed in less than 30 minutes. I really hope that I'm just unlucky but I feel the production hasn't been made seriously.