Huh, that’s weird. Double checking the part markings would’ve been my next suggestion, but the picture shows they’re correct. Maybe try a 1kOhm load resistor across Vout and GND, though in theory you should be able to see the output voltage without it.

Just to be sure: positive probe on Vin, negative probe on GND, measurement shows no minus sign?

Unlikely. Have you measured the voltage present at Vin?

You’re welcome!

I haven’t got enough time on my hands right now to review the whole desingn, but one thing that jumps to mind is that you’ll want to use an antiparallel diode on each relay coil to suppress the negative voltage spikes when switching it off.

Be sure to keep adequate distance between high and low voltage traces. The ground plane seems awfully close to the N trace.

Other than that, I’d happily welcome more PCB and/or personal project discussions!

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