Adam
No, we removed the micro from the board. The specified pins on the micro itself are showing 2 ohms from some of the VDDIO pins to ground. Once the micro was removed, the board resistance went to back up to about 750 ohms from 3.3v supply to ground.
Basically, the problem followed the micro chip. Here is a "corrected" list of pins:
Pin Ohm MCU Circuit
--- --- --- -------
67 2 VDD10 3.3V
74 2 VDD10 3.3V
92 2 VDD10 3.3V
94 2 VSSOSC nc
119 5 VDDA1 3.3V
134 5 VDDA2 3.3V
The million dollar question is how did this happen? Our board functions correctly during many power cycles before this happens on the next power up cycle. Once it happens, our 3.3v DC-DC converter goes into current limit (around 1 amp) and can only bring the 3.3v line up to about 0.80 vdc because the board 3.3v line is only 0.5 ohms or so above ground. Remove the micro chip and we see the above.
Thanks,
Casey
