DIAGNOSIS The machine has power and the main board is working (hence the beeps), but the LCD screen itself has failed or become disconnected. This is a known failure point on this model.
FIX First, try a hard reset. Unplug the machine, then press and hold the Power button (the physical button, not on the screen) for 15 seconds. Keep holding it while you plug the power cord back in. Wait another 10 seconds, then release. This can sometimes jog the display controller back to life.
IF THAT DIDN'T WORK The connection is likely internal. There's no user-serviceable fix here beyond checking for obvious water damage near the control panel. This generally requires a warranty service call or replacement of the front control panel assembly.
HEADS UP You can still operate the machine blind if you memorize the sequence. Power button turns it on/off. After the 'HELLO' sequence you can't see, pressing the physical 8oz, 10oz, and 12oz buttons will still brew those sizes from a K-Cup. The carafe button is the one furthest to the right.