Fridge only staying cold for 12-14 hours on AC

I'm showing I believe it was 121.4 Volts coming into the board. I'm going to pull the fridge back out this weekend and check the flue and I'll try it in the other sleeve. I just put the new one in exactly as the old one was.. So what's your theory Doug as to why that would allow it to cool for my usual 14-16 hour period and most recently nearly 5 day period before it decides to quit cooling again? I'm just trying to rationalize this.