How to Troubleshoot & Replace Lg AP4440232 / 6871ER1003C Main Printed Circuit Board

Through my research it could've been the control board or main board. If you know what item on the board to test with a meter you can then determine which board to replace. I did not have that option and took a chance and replaced the main board and it turned out I was right. The plastic cover that covers the main board had a sticker on it with a serial number. Pay no attention to this sticker because when I pulled out my main board itself it had a different serial number on the board and I used that one to order the replacement.Repair was fast and washer powered up fine. 

LED light on main circuit board was not lit, verified that it was getting power by testing filter for 120v compared two circuit board options and ordered the one we had in our unit. took about 30 minutes to replace, 4 screws, and several plugs. Powered right up, and is now working. Much better than buying a new unit.