I just bought a nearly new used fridge to replace an older unit. I got it home and let it sit overnight, although I did transport it upright. The next day I plugged it in and it got cold very quickly and seemed to work great. The manual says to wait 24 hours to see any ice production, and that it may take up to 3 days to fully fill the bin the first time.

I waited a full 24 hours and I think I had about 8 ice cubes in the bin. I dumped those and waited another 24 hours and had maybe another 10 new cubes. I waited another full day and had maybe another 12 new cubes. Seeing some small increase in production I thought I would wait for the full 3 days before worrying too much about it. I dumped the 12 cubes and waited overnight, and had no ice the next day.

I then turned on the 'fast ice' feature, which is supposed to increase ice production for the next 24 hours. It has been 24 hours now, and I again have 0 (no) ice cubes in the bin. The 'fast ice' feature has turned itself off as it should, but still no ice. I am always a little skeptical with something new and not knowing what to expect, but I have had it plugged in and going for a full 4.5 days now, and at first it seemed the ice production was increasing, and now it seems to have come to a complete stop.

I am not very familiar with this system. Where should I start and what should I check? Here is what I know: the water works great at the door. The fridge and freezer seem to be plenty cold, if not sometimes dipping a little colder than normal (see below--although I don't think I would have been able to tell or would have known that had I not started taking actual temperature readings). I don't see any damage to anything. I had an older whirlpool unit with the ice maker in the freezer compartment with the optical sensors on the side panels that blink. This one has optical sensors behind the ice bin in the door, but I do not see anything lighting up or blinking (but I don't know if it should on this one). What is my next step to figure out if something is wrong?

Also, how much temperature fluctuation is normal in a modern fridge and freezer? I have a thermometer in the unit and it seems like the temperature can vary by 5-10 degrees each time I check it (usually several hours apart). Is this normal or should it hold fairly close to where I have it set?

No ideas on this? I am over a week now, and I have a total of about 1/2 bin of ice. Need help!