ESD protection CP2105 (U54, dual UART)
Although ESD protected, SiliconLabs CP2105 (U54, dual UART) seems to be a weak spot. It happened two times on the CLB of KM3NeT and once on the SPEC7v1 that the CP2105 is failing. Consider to replace the CP2105 by the FTDI FT2232HL which seems to have a better track record.