So, an update after a month. I ordered a new power adapter from Aliexpress, instead of doing some more testing. It finally arrived and the wheel is still dead. Checked the voltage on the adapter with a multimeter, that's seems fine. Chances that it has the same problem as the previous one I guess are small, so most likely it's something in the inside of the wheel, which is really sad. Thanks for trying to help and I at least learned a few things.