looking for defrost timer

[app1]

Looking at a Frigidaire refrigerator Model# LGHS2665KF2 and I can not find the defrost timer - Is it in the main board and not seperate. ALSO Question # 2 is how would I put this thing into defrost??? Thank you for your help!

[AJ]

Taking a quick look at the wiring diagram I can see that the defrost system is controlled by the main board.
Not sure how you would put this one into defrost off hand, but if you clearly have a defrost problem I would check the defrost heater and deforest thermostat for continuity with a multimeter.

If the defrost heater and defrost thermostat check ok then you must have a problem with the main board.

Here are the parts and wiring diagram for model: LGHS2665KF2

[app1]

Thank You AJ I will  test these first, then if they are OK we are looking at replacing the main board. Thanks Again!!!!!!

[RegUS_PatOff]

To activate manual defrost, simultaneously press and hold the Fresh Food up (+) and Fresh Food down (-) keys for 5 seconds.
 
A "d" in the freezer temperature window and "F" in the refrigerator temperature window will display when the heater is activated.
 
To deactivate manual defrost, simultaneously press and hold the Fresh Food up (+) and Fresh Food down (-) keys for 5 seconds.
 
A "d" and "F" will be displayed until the defrost cycle is complete.

[app1]

Thanks regus, I put the refrigerator in defrost and the heater did not come on and the fan contined to run, I then noticed the wire going into the heater was NOT pushed in all the way therefore not making contact. I pulled the wire out only to find ice build up inside the female end, it must have been building up until the ice became an iceberg so to speak and forced the two wires apart. Cleaned out the ice-reconnected-heaters came on and everything is working fine. Very unusual though!!!
Thanks again to all for the info.....