Model Number: 550
Brand: Sub Zero
Age: More than 10 years

I have a 25 year old Subzero 550 that is in excellent condition, and have owned it since new. Last year I had the compressors replaced and it has been running and cooling perfectly.

Recently the ice maker stopped working. It is not the original, as it has been replaced several times over the years.

I replaced both the ice maker and the water valve. It is still not working. I then decided to defrost it to make sure the fill line wasn't frozen, so I left the entire unit unplugged for 6-8 hours, then reconnected everything.

The water line is good with good pressure. To test the valve functionality I took an electrical extension cord and attached spade connectors to one end and attached these to the ice maker. I then applied direct power to the water valve by plugging in this cheater cord for a 7 second count, and the ice tray filled with water, confirming that I have adequate water pressure, and that the fill line is patent and able to flow water to the ice tray.

What else should I test or trouble shoot? I have a repairman coming out tomorrow if all else fails, but I would really like to try to fix this myself.

Thanks in advance.