Phone not recognized

I have recently updated my iMac to OSX X 10.11.6. I am running iTunes version 12.5.1.21. I have an iPhone 5. I just went to backup my phone and my computer is not recognizing my phone at all. It isn't even charging it when I plug it in. I have a keyboard plugged in to the usb port, but that is the only usb port being used. I have tried plugging in to each port (even moved the keyboard to a different port and tried the port the keyboard was originally plugged into), switching cables, restarting my computer, and doing a hard reboot of my iPhone. Nothing is working. This link is useless: If iTunes doesn't recognize your iPhone, iPad, or iPod - Apple Support

When I go to system info like the article suggests, it doesn't have the iPhone listed. Help is appreciated. 🙂