No, I do not get the sequential blinking lights. If I connect the ESCs directly to the Rx I can control the motors with my Spektrum Tx, so I know it isn't the wiring.
I took it to an expert builder and owner of a flight school to exclude anything dumb on my part.
We noticed some of the solder was not complete on the board to the RPi, so I added more solder. I also re-flashed the SD card. After this it still does not work.
I do see the green, orange and blue light and the ESCs are beeping. The RPi light is on and I can see it booting.
Is there anything else I can do to troubleshoot? I have been working on this for weeks, and now getting to the point of abandoning PXFmini in lieu of a more traditional FC.