nDC_PWR indicator rev C xM

I have a Rev C xM board. I wish to monitor the “on DC” signal that the
schematic shows coming into GPIO 6 on the TPS65950.
I know my software is correct as I can read GPIO 0 which is the SD
card detect signal and I can see it toggling as I insert and remove
the card. When I move it to GPIO 6 it shows high all the time even
though I am powering from DC.
I probed with a scope Q2A collector and it shows the pin high (1.8v)
which should not be the case with DC applied (DC_IN is 5v). It looks
like the transistor is not turning on.

I also probed while just statically sitting in the boot loader, so the
GPIO pin mux should be configured as default (i.e. input). I checked
the registers and they are inputs so the pin is not being driven from
the TPS65950 side.
Has this circuit been tested? Could it be R144 is too high?

I just checked and that circuitry is not working correctly. We are getting leakage back through U31 that is keeping the transistor on.So for now consider that circuit inoperative.

Gerald

Thank you for the feedback.

David Vescovi