Our analysis found that they both had damage to the Load Flexible PCB (L) for the CN5 Connector. We determined that the direct cause of a malfunction of the mechanisms was a crack in copper terminals at the boundary area adjacent to the coverlay; however, as you can see the attached reports, these Flexible PCBs also had either a dent or an abrasion mark on their exposed areas. They are different in the shape but are located in almost similar places. They might be the evidence that the Flexible PCBs / mechanisms were subjected to external force.
Specifically, the external force is more likely to have caused the crack in the copper terminals and broken them.