Maytag MFI2266AEW auto defrost problem

[steve66]

This fridge (12yr old)came with the house I bought 6 months ago and worked great till a few weeks ago. Coils at the back of the freezer started freezing up. Went through all the service test mode functions and everything looks good. Forced defrost mode also still works. The only components I can see in the auto defrost circuit are the control board(67006294) and defrost T-stat. I found a 'refurbished' board on Ebay and swapped out but still had the issue. Installed a new T-stat but that wasn't the problem either. I'm starting to think the used board has the same issue as my original. Am I missing something? Is there an easy way to test either board? Can't keep doing a forced defrost every 4 hours!

Appreciate any help anyone can give me.

[16345Ed]

Part number: WPW10310240

This is the board that controls defrost. If it went into forced defrost that proves thermostat and heater are good. Need new board. 

[steve66]

That would explain it! I was assuming the front panel board controlled it! Let's hope I can find one.Thanks for replying