Water valve will not shut off

I have a Frigidaire Z(FRT18L4JB1) refrigerator with an ice maker. The ice maker has never been used. I connected water to it and the water valve did not shut off so it kept filling the ice tray then the freezer compartment. I ordered a new water valve and installed....same result of valve not sealing off. I tried a valve from another refrigerator. It leaked by as well. I replace the puncture type water valve under the sink with a "T" and in line valve. Still the same result. Just connecting the water to the valve with no electrical connection, each of the 3 valves leak by. Please tell me what I am missing! Thanks, Scott