My ice maker stopped working a while back. I took it out and looked and it and could not see anything wrong with it. I put it back in and it started to work normally again. A few weeks ago it stopped again. I took it out again and this time the bottom coil was hot. I thought it may have been stuck in the defrost cycle for the cubes. I put it back in and it worked again for a couple of weeks. Now it stopped again. I tried to put water in the tray and it seemed to cycle them out. Now it appears that if it is working that it is not filling the tray completely. I took it back out and removed the cover from the gears and everything appears to be OK, no broken pieces.
I don't know what controls the operation and don't want to spend money on a new ice maker if there is another problem somewhere else.

Any suggestions?