Hi, thanks for responding. I already tried different cables with the same result. Also, it is not clear how the cable could make the signal level too high, so I am still puzzled by this error.

A PicoVNA that has been sitting unused for a long time fails its hardware diagnostic test. See attached picture of the resulting dialog box. The test procedure has been followed, with several attempts. Is this a user error, or an actual hardware failure? In the latter case, is there a known solution...