Product review (5 stars): Saved us Over $100
Our icemaker stopped working one day, with no apparent failure mode.  The little light on the side of the freezer was just blinking.

I checked things out with a multimeter and it appeared that it was sure that the ice was full, even though we were out.  Using my cell phone camera (which sees into the IR spectrum) I could see that the emitter wasn't working.  This set of parts was over $100 cheaper than the local Maytag store.

If you think your icemaker needs this, one thing to check is to use a cell phone camera looking at the left side of the freezer, just inside the door hinges.  There is a little hole, and inside the hole is the smaller board seen here.  This is an infrared emitter.  When the ice fills up, it blocks the IR beam and keeps the larger board on the right from seeing it.  That's how it knows the ice is full.  Unfortunately, if the emitter dies, the board doesn't see it either, which means it thinks your ice bucket is always full.

If you use a webcam, cell phone camera, etc, you can usually see the flashing emitter.  One way to make sure your camera is capable of seeing into the IR spectrum is to point a TV remote at it.  If you see it light up, you should also see this one light up!