How to Troubleshoot & Replace Lg AP4450216 / EBR34917104 Main Electronic Control Board

Kept getting the ER DH code which has something to do with the defrost in the freezer. According to the downloaded service manual it was either a sensor or control PCB. I changed the sensor first since it was only $18. Two days later getting same code. Changed PCB and for a week have been error free. 

Had a tech replace both parts. 

Replace main board 

Replaced Main Electronic Circuit Board On Thursday morning I came downstairs to a dead refrigerator. I unplugged it for a few minutes and after plugging it back in it briefly stayed on for a few seconds with a blinking front panel before shutting off. After an internet search of the symptoms, I suspected a failed main circuit board. I subsequently ordered a new board from AppliancePartsPros that arrived Friday morning. By the time the new part arrived, I had already disconnected and removed the old board. I promptly installed & connected the new board. Said a quick prayer before plugging that baby back in and SUCCESS! Back in business without the expense of buying a brand new refrigerator! The geek in me always thinks repair before replace and I'm thankful it paid off this time. 

Changed the mother board. 

My Kenmore fridge no longer had working lights. I tested the door switches and they were functioning. I decided to replace the control board which was a very simple repair. The control board is located on the back of the fridge. The rear cover is held on with three screws. Simply unplug the connectors, remove the old control board, and plug in the new control board. This repair took less than 5 mins and now the interior lights are functioning. 

Ordered main electronic control board. Watched video on replacing. Very easy to do. Refrigerator working perfectly now! I Ordered part on a Friday and received on Saturday! No food spoilage. Very thankful to appliance parts pro. I also saved a bundle of money doing it myself. Thank you for your help and expertise. 

Checked the wiring diagram on the back of the fridge and isolated the concern to the relay on the main board. Quick google search verified this was a problem on my fridge model. Unscrewed the bulbs while waiting for parts. Replaced the main board and also replaced the incandescent bulbs with LEDs. Even if it fails again the LEDs should keep things from posing an immediate fire hazard. 

The part came fast, two days, despite shipping in the heart of Christmas delivery season. Replacing the board is easy, about a five minute job once you have access to the back of the fridge. You only need a phillips screwdriver for the access panel, everything else is push tabs. The connectors are all different sizes (it appears), so you shouldn't be able to plug things up incorrectly, but it wouldn't hurt to take a picture before you start disconnecting harnesses. The longest part of the process will probably be moving the fridge, cleaning off years of crud, and replacing the water line while you are back there. 

Tried switch replacement and light housing replacement; both actions unsuccessful. Replaced the main control board (not cheapest option) in less than 10 minutes. And, there was light!! I am very pleased with AppliancePartsPros!