KK S49 MKII WON'T TURN ON

First of all, I bought my keyboard about 2.5 years ago and I couldn't sleep from excitement when I first got it because it was the first MIDI keyboard that was mine. Also, I am a student living alone in Istanbul, so believe me, it's not easy for me to afford this kind of stuff. I will not ignore the good times I've had with it over these years, but I also cannot ignore the fact that this keyboard is willing to do absolutely everything to slow down your workflow. The product always feels like I am testing some beta version with all the bugs and flaws. Putting aside the hassle it causes to integrate with any DAW, it never works seamlessly even with applications within its own ecosystem. There is always something that needs to be fixed first. Previously, I reported to the support team (back when they had a proper support team) that some buttons (mixer etc.) would stop working and their functions would be disabled after a while when working in Ableton, and no matter how much we tried, this problem was never resolved. So, every time I need to use the keyboard, I reinstall it first. Today, however, the keyboard won't even turn on. I press the button, and nothing appears except "Komplete Kontrol" on the right screen and "Smart Keyboard Controller" on the left screen. I checked and followed everything listed on the website meticulously. I checked all the drivers, reinstalled them multiple times, and tried different cables, different USB ports, and even a different computer. The result is still the same, of course. I'm really tired of dealing with these problems. I want to sell it and get a more stable and reliable keyboard, but I don't even know how to sell it with this problem now. Sorry NI, but this is a komplete disaster. I will never buy a product from this company again.

Here's a picture of the problem, as if some other people didn't post the same problem and weren't left unresolved.