The eyebrow is what the user uses to control the refrigerator. He can select Auto, DC, or gas and set the temperature. On the 8600 series Elec is an option instead of Auto. The graphic below is the eyebrow for one of the later model 600 series refrigerators. It has the On/Off Humidity switch, which isn't a part of this discussion. Older versions of the 600 series have this switch mounted on the plate between the two doors of the refrigerator. The switch is covered on the Second Generation Home page. On other models, the humidity switch just controls the defrost heater between the two doors and doesn't turn the entire refrigerator off and on.

A generality with eyebrow controls is how to isolate a problem between the eyebrow board, Power Supply Board, and the modular cable that goes between the two boards. If there is 12 volt to the eyebrow board and the appropriate light doesn't work, the eyebrow board is the problem. If there is no 12 volt to the eyebrow board, the cable or Power Supply Board is bad. Check connections at both ends of the cable and, if good, change the Power Supply Board. If the lights work on the eyebrow board but the Power Supply Board is not putting out the proper output (i.e. 120 volt to the 120 volt element), then the problem is the cable between the two boards or the Power Supply Board itself. Check connections at both ends of the cable and, if good, change the Power Supply Board. These are only generalities and there are exceptions to everything. Also, the assumption is made that you have tested input voltages and fuses where appropriate.

A few points about the eyebrow circuit board. First of all, it looks backwards in terms of the eyebrow picture above. This is because the circuit board is installed into the eyebrow upside down. Also, although the board shown is for a 600 series refrigerator, the board will have Elec and AC written on it instead of what should be there. That's normal and just shows how closely related the 600 series is to the older 8600 series. On the 8600 series the user would select Elec and then choose between AC and DC on the 3 way models. However, The boards are not interchangeable.

One test for the eyebrow board, if it's dead, is to test for voltage between the diode D11 and resistor R22 (R23 for 3 way models). Notice in the graphic that the arrows identifying the components point more to one end of the component than the other. Those are the ends you should test across. You should get a reading of 10 volt DC. If the voltage is present and the eyebrow doesn't work, the eyebrow is bad. If there's no voltage, the problem is either the modular cable or the Power Supply Board. Check the connections on the cable and then, if the connections are good, change the Power Supply Board.