Venue 11 Pro 7140 Not Playing Right Channel Headphone Audio

I just finished setting up a never-before-used Venue Pro 7140 with preloaded Windows 8.1. The audio is fine out of the internal speakers, but the right audio channel is silent from the headphone jack regardless of what Dell Audio settings or pair of headphones I use. I've looked  for troubleshooting, but everything I find is for audio in general and/or applies to problems on the left and right channel simultaneously. What can I do to fix this?