Re: External Vref on PIC32MX570F512L
Just noticed that the latest errata for this family has some additional items including #17, which indicates that under some circumstances I/O pins "can be in an active random output driving state if MCLR is active until a BOR event". One work around involves removing the 0.1 uF cap to ground, which our device still has. I wonder if this could be the issue. Until this latest round of boards, we were not using any port A pins.