820-2879: AHT error 4sns/1/40000001:tn1d--1.000 : CPU heat sensor issue?


New member
Greetings - working on an 820-2879. Boots fine but locks up after running for 5 or 10 minutes. Getting AHT error macbook 4sns/1/40000001:tn1d--1.000. My best research shows is it's a cpu heat sensor. I checked around U5515 and also Q5501 but no damage anywhere. I was going to change these out but wanted to make sure I'm in the ballpark before I turn on the heat.



Thermal sensor issues would never cause it to lock up. I bet this had impact damage and traces are damaged under MCP/CPU. This board is done. Unless there is corrosion somewhere of course.

Is the piece of tape present on the airport connector, this will also cause lock ups. Remove the metal sponge from the cable.