Yea I have the same exact problem with my DIC. I bought the car a month ago with it not working and I found out it wasn't plugged in so I did and found out the same lights do not work. Replaced the bulbs with #24 bulbs and the LCD backlight still doesn't light up. Switched the bulbs with ones that do light and same issue.

Before I took it apart the LCD worked as I could barely see the info but it worked. Now the LCD isn't even turning on. My only solution now is to replace the whole thing.