Core X Chroma not turning on

Hello guys, I've been using the Razor Core X Chroma for a few years now and I'm very happy with it as well. However, as of today, the eGPU no longer starts. I can't see any USB devices connected to the eGPU. Unfortunately, the warranty has expired. Has anyone of you ever had the same problem and may have a solution? Voltage seems to be on the 24pin connector of the PSU, I measured that. Come but now no further what I can still test. I use the eGPU with Windows and Linux on a L14 and t480 Lenovo notebook, a new Thunderbolt cable I have already tested. I tested it with and without GPU (tested with GTX 1060 and RTX 3070) thx for help!!