Before attempting any repairs or testing, check out the electrical safety pages.

The Power Supply Board controls and activates all of the heat sources (AC, DC, and gas) of the refrigerator. It requires 12 volt power at all times for the refrigerator to work on any heat source. The Power Supply Board takes its settings from the eyebrow board and proceeds accordingly. It has the job of determining if AC is present, for example, and switching to gas if it's not. It provides voltage to the Ignition Control Module when gas is selected, and sends voltage directly to the 12 volt element and 120 volt element, when those heat sources are selected. The board shown below is for a 3 way model of the 600 series. The 2 way version would not use terminals J2 and J5, nor the 20 amp fuse. The 8600 series and 8700 series boards are different.

One thing to note on this board is that the two blue wires leaving the board at the top complete a circuit through the On/Off Humidity switch. If you were to disconnect the two wires from their connectors on the wire harness going up the back of the refrigerator, and then connect the two wires together, you would by-pass the On/Off Humidity switch. If the switch was bad, this would allow the refrigerator to work. In fact, the single door models, like the 6053, don't have the On/Off Humidity switch and come from the factory with the two blue wires connected together.

Wiring Code for Circuit Board
1Interior light (-)
2DC heat element (-)
312 volt (-) to battery
412 volt (+) to battery
5DC heat element (+)
6AC heat element
7AC heat element
8AC in neutral
9AC in hot

Troubleshooting the Power Supply Board is a matter of testing what should come in and go out of the board. See the table above for information on that. Also, the fuses on the board should be tested. To access the fuses, the cover has to come off the board. Unplug the refrigerator, then disconnect all the wires going to terminals on the board. Pull the cover, then reconnect the wires for testing if necessary. This is also a good time to inspect the board for burned spots.