Apple Hardware Test Error 4Sns C0000008 Ts0P 124 Macbook Pro 13 Unibody Early 2011

Chosen Solution

MacBook Pro early 2011, A1278. Everything boots up but is very slow loading. Fans is running loud. Replaced the heat sink, Trackpad, Fan and I still get the same error code: Apple Hardware Test Error: 4SNS/C0000008:Ts0P–124 Now what? Help! Update (02/05/2017)

Sounds like you have some corrosion on the trackpad. Either clean it carefully with some 85% isopropyl alcohol or just replace the trackpad. Here’s the IFIXIT guide you’ll need to follow: MacBook Pro 13" Unibody Early 2011 Trackpad Replacement

I had this error too! I tested the original trackpad & cable in a new machine, error gone. Searched the web and people said the webcam cable could also be to blame. Disconnected webcam cable. All issues stopped.