Help! Need BBG to replace failed BBW but having gpio problems

[wku...@gmail.com]

I downloaded the "latest" Stretch image (bone-debian-9.2-iot-armhf-2017-10-10-4gb.img.xz) and had ho issues moving my code to it and compiling it.  But when I attach my hardware interface to P8 connector it won't boot.

I've edited the /boot/uEnv.txt file and un-commented: 

   disable_uboot_overlay_emmc=1

but it made no difference.

What am I missing?

If I plug in my hardware after it boots and run my code all the /sys/class/gpio/gpio*/value and direction seem correct but it doesn't work, for example gpio39 (P8_04) value cats 0 and direction cats out, but a voltmeter on P8_04 reads 3.3V