A common problem with the older Blink EV WE-30 Chargers is a failure of the touch screen. The most common problem is a failure of the little black connector for brown/gold ribbon cable that connects to the touch screen.  You need to apply deoxIT to the small black connector on the lower board. Using long nose pliers pull the black latch out ~ 1/16" and that will free the brown flat cable,  Apply deOX it to the cable end and reinsert the cable and push the black latch back in,  Power up and test.  NOTE: you normally do NOT the need to recalibrate the screen. Just wait ~2.5 min and you should be ready to go.