Pimax Artisan only shows red LED (dark and bright)

Why shows my Artisan only red LED?
PiTool says DP and USB 2.0 isn’t connected, but there is! It ran some days, but suddenly it didn’t boot anymore.
PiTool Diagnostic doesn’t work (I think). It only says, that only USB3.0 is connected and nothing else. It says the same when the headset is disconnetcted completly.
What’s the problem?
All PC components have the newest drivers. Graphics card is GTX 1050Ti and CPU is AMD Ryzen 5 1400, DX12 is installed too.