U2415, can't get to Menu, only shows Input Menu

I know it's getting a bit old but I have a trusty U2415 that I've been using as a vertical second display. Today when plugging it into my MacBook Pro I got an error saying it was a USB accessory using too much power. I wanted to try disabling the DDC/CI for the U2415 but all the front panel buttons show the same menu: Input selection. I can't get to the actual Menu settings. I've tried unplugging everything from the monitor, waiting 15 seconds, re-plugging in the power cable and trying again, but no luck.