Fridge kscs25fjss01 - Defrost heater doesn't get hot during test mode

[nelaco]

Hi everyone, my fridge has been warm (55 F) for a few days now, and the freezer at about 15 F.  The evaporator was full of ice so I tested the defrost thermostat, fan motor, and defrost heater on the bench and they are all ok.  I then entered the fridge into Test Mode and everything checked out ok except when I test the Defrost Heater it doesn't get hot (on the bench it showed continuity @22k Ohms)

Is there anything else I need to test?  I've read about a "Defrost timer" but I am not sure where it is located and how to test. Should the defrost heater get hot during Test Mode?

Thank you in advance for any help you can give me.

[vee8power]

1 hour ago, nelaco said:

Should the defrost heater get hot during Test Mode?

Yes, when you activate the defrost circuit in diagnostic mode.

It sounds like your diagnostics have done so far have led you to the control being the failed component. If you feel confident, you can check for 120 volts between the pink and white wire on the main  control board while you have the defrost activated- no voltage means the main control needs to be rebuilt; new ones aren't available

Edited March 19, 2020 by vee8power

[nelaco]

Thank you vee8Power.  Sure enough, NO voltage at the main board between the pink and the white wires while on test mode/defrost heater.  Do you know of a place that can rebuild my board or maybe sell refurbished ones?  I am having a hard time finding them online.  I've had the fridge for almost 20 years and it's been solid.  I would hate to trash it due to this.

Thank you again!

[nelaco]

Never mind vee8Power, I found a refurbished one online.  We'll see how it goes.  One year warranty so it should be ok.  Thank you again!

[nelaco]

FYI, I replaced the motherboard with a refurbished one and the fridge has been running perfectly.  Thank you again for all your help.

[PhilipPixler]

Bet you could recoup some costs by trying to sell that board on ebay. If it's being sold as refurbished someone will buy it to refurbish it.