KitchenAid refrigerator did not work

Refrigerator & Freezer Repair
1

The Symptoms is the “over temperature” light is always on. The refrigerator did not work at all. The light is occasionally on just 0.5 second and off. The temperature on both side keeps rise. I do not know which part I need to replace? Inverter control box or Main control board or others? I tried to turn off the main switch and turn back on, same thing. So I asked the technician on this website and got answer as follow:

Not likely an inverter could be the control board, but check the defrost drain pan and system for overflowing or clogged evaporator or bad evaporator fan first. Also make sure both doors are closing and sealing properly. If ok replace control board which has now been discontinued.

I tried to research the internet regarding how to check the defrost drain pan and system for overflowing or clogged evaporator or bad evaporator fan, but I could not find these information. Could you please tell me the steps of how to check those things mentioned above, or send me some video links?

I really appreciate your help.

2

Ok, so nothing is running? No fans, no compressor, etc..? Interior lights flickering? No or intermittent display? I doubt it is the inverter; that runs the compressor depending on instructions from the main control.

I seem to recall doing an entire control asm for these units a while back. It was a substitution for the original 2 board set up I think. In that case it restored full function. I also recall that it was a pain in the butt to install correctly and $$ for the part but the unit had matching cabinet fronts and replacing was very $$$$$.
I’ll try to remember to look it up when I have access to service bulletins tomorrow to see if it is the same unit or covered under same bulletin.