I know that this sounds crazy, but . .
I removed six working maxbotix EZ0s from the LEAF robot that I disassembled. They were all working.
I wired them as directed (no brainer.)
None of them worked. I hooked them to the ADC ports. I tried all ports and all sensors.
I tried several ways of wiring them. No soap.
I even tried them on Digital.
I am beginning to think my ADC ports are not working.