BeagleBoard GPIO issue

I’m having a problem with the GPIO pins on the BeagleBone Black RevC manufactured by GHI. I am unable to configure GPIO pin P9-15 as an output using Adafruit_BBIO.GPIO. I’m booting from an SD card and running Python code that works fine on RevC BeagleBone Blacks from Element14 and Embest. I have tried multiple GHI units to no avail so It does not seem to be a one-off issue. I’m running kernel 3.8.13-bone47. What could be different about the GHI BeagleBones?

There are not be any differences, except for what software you have loaded. Are both boards running the same default image from the beaglebone website?

Gus,

I have tested many boards from the three manufacturers booting from the exact same uSD card so the software is identical. I did some more testing and have found that only P9-15 seems to be affected. All of the other GPIO pins on the BBB behave as expected on all of the boards. Is it possible that we got some boards from a batch that has some sort of hardware issue with that pin? Is it possible that there is a firmware or silicon difference? I have custom daughter boards made for a large application that utilizes that pin. When I switched to using the GHI boards they stopped working due to the inablility to drive P9-15. Thanks for you help.

Very strange. We are not aware of any silicon changes. I would get the beagleboard involved as this is something they need to know about for the sake of other customers.
https://beagleboard.org/support