Control panel / fridge not working, but has power (interior lights do work)

Love my refrigerater and had worked fine until it woke us up in middle of the night. My son was up first and said "fridge went nuts and woke him up". When I came in the control board/user board was flashing and could not stop it. I unplugged it and plugged back in but still flashing. I pushed stop bottom left corner on control panel, and not sure if that's what made it stop or not, but it stopped and now nothing is working but interior lights. I did order and replace the start relay which was suggested by sears parts direct to replace first, but honestly can't be sure that was a good part either as it was unprotected in a much bigger box delivered in and when shake it rattles a bit, same as the old one. They suggested defrost timer next. I just need to know what part without replacing entire fridge. Defrost timer, control board, main board, I have found no reset to my knowledge. See no visible issue with either board. HELP WANT MY FRIDGE BACK, NOT SENT TO GRAVEYARD LOL