Q: My iPhone SE wont connect to my Macbook

Hi TheGodric,

Thanks for checking out the Apple Support Communities! I understand that you're having trouble getting your Mac to recognize your iPhone when you plug it in. I like to be able to sync my iPhone to iTunes for music and movies so I can understand the importance of making sure that your iPhone is recognized by your Mac and I'm happy to help. 

The first thing that I recommend to do is unplug your iPhone from your Mac, then restart both your Mac and iPhone.

How to turn on or turn off your Mac

Restart your iPhone, iPad, or iPod touch

Once you've restarted both your Mac and iPhone you'll want to verify a few things before plugging back in. If you haven't already, you should try plugging in to a different USB port on your Mac, if available. I also recommend trying a different USB cable. You'll also want to make sure you're plugging directly in to your Mac and not a USB hub, other USB powered device, or any USB ports on an attached external keyboard. You can also test this out if you have any other iOS devices like an iPod or another iPhone to see if the same thing happens. If you have another Mac available, you can also test further by connecting to it to see if the same thing happens when plugged in. These troubleshooting steps can help narrow down where the issue is happening. 

If you're still having trouble after going through those steps, it's possible that your Mac is not putting out enough power to properly charge the iPhone you're plugging in. I recommend to take a look at the following article for more information:

Apple Computers and Displays: Powering peripherals through USB

Cheers!