Chosen Solution

Has anyone had issues with y motion not working correctly after replacement? Is this because the trackpad cable is loose? or installed incorrectly? or is it a faulty trackpad?

I would replace the trackpad and the cable MacBook Pro 15" Unibody (Mid 2009-Mid 2012) Trackpad and here’s the guide MacBook Pro 15" Unibody Mid 2012 Trackpad Replacement