Hello @tomas_hora, I've connected the notebook power supply once to R2.1 and once to R2.2. On both relays, after switch on the contacts are connected forever. R2.3 was never in use and is still working (shared COM with R2.2). Even if I disconnect everything, including UniPi power supply, the contacts R2.1 and R2.2 are in on state.

@tomas_hora Hi. I have the same behaviour. After switching the power supply of my notebook, the relay is always on. The noise of switch-on is the same, but the noise of switch-off is quieter compared with a working relay. The power supply is rated with 55W / 230VAC. Maybe the power on peak current welds the relay contects?