thanks for the answer. I filed a support ticket.
I have the exact same issue. I started my rytm and it got stuck at the startup screen when all colours flash over the pads. It froze on the last pad with color blue.
Tried a facorty reset and empty reset but it got stucked over and over again on the startup screen. Then i tried a os upgrade, and a downgrade to another OS via MIDI - DIN from the early startup menu. Both times with the same result that it got stuck on the startup screen.
Only difference i could notice, that it started to freeze at earlier points. at the beginning all colors flashed through with a freeze with blue. Now it even gets stuck after a sec with pink and just saying
analon the screen, which kind of even fits quite well to the circumstance that it doesnt start.
When i try to start it normally it gets stuck earlier as it gets stuck after the reboot from the factory reset from the early startup menu.
Support responded that the cables might oxidized and suggested I can try opening it and check the contacts, which I did. All seems fine. I strongly suspect it to be a software related issue.
Could you please check if you have some information on the repair bill . Usually they say what was broken, resp. what has been done to fix it. Can you remember if they changed some parts or charged you for some?
Thanks so much for your answer