The ice maker in in Samsung RF267 fridge isn't working. It occasionally makes a cube or two, and often will make an intermittent knocking sound (like buzz buzz buzz, knock), but that's it. The filter is fine, it's getting water, etc. I tried the "test" button, and it's supposed to make a chime after holding it for 8 seconds, but I have yet to hear a chime, and I've held it for much longer. I am getting water from the door dispenser.
Any ideas?

Edit: I pulled the water inlet valve and checked for resistance across the terminals. Nothing. I'm not super-sure about using a meter. It's digital, and when set to the lowest ohms rating, it read "1" in the display. When I touched the probes to each other, it jumped up, but never settled on a single number. When I checked the contacts on the valve, it still read "1" and never changed. Is it the valve? We still get water, though.