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Replacement parts for srde27s3e models | AppliancePartsPros.com

[COLOR="DarkRed"]If I get voltage from the board when "forcing" a defrost cycle, does that mean the timer is working? Will it come on by itself?[/COLOR]
Not totally. It does tell you that the relay or triac on the board works. It does not tell you if the board will actually do the timing function and start a defrost cycle on it's own.

[COLOR="DarkRed"]I am trying to see if the problem is the timer or the heater itself.[/COLOR]
Unplug the unit and reconnect everything.
Remove the cover from inside the freezer so you can see the coils.
Do not defrost them.
Now try forcing a defrost.
Does the defrost heater come on.
Be careful that you do not burn your fingers.
If yes then I would replace the defrost board.

Note: the defrost thermostat must be frozen for the above to work. It opens just above freezing.

If the heater does not come on check the heater itself (usually around 20 ohms). Also check the defrost thermostat (should be 0 ohms).

Visually check the defrost thermostat , if it is bulged replace it even if it measures good.