Hi @Montecri,
The analog mux used to switch between the various voltage measurements can have a large settling time depending on various factors (corner cases, temperature, etc). I was pushing it a bit faster than it should go.
I ran the self test and my VUSB was also out of spec at 4.x volts. The mux is grounded between measurements to eliminate stray capacitance (or we see ghost readings). However, it was reading before there was a chance to fully rise from 0volts to VUSB (~4.75-5.25votls). I increased the settling time to 60uS and everything seems good on my board.]
I suspect this will also fix the SD card issue. Due to lack of pins on the RP2040 we read the card detect pin through the analog mux as well. If there wasn’t enough time to settle the card might not reach the voltage threshold to be detected.
Please let me know if this help. If it doesn’t help, could you please paste (or screenshot) the output of the i command information screen.
Cheers,
ian