Samsung's suppliers moved to replace those batteries with safer versions, but in their haste, a completely different production flaw was introduced. Welding defects inside the batteries made those supposedly safe replacements prone to short-circuiting and bursting into flames as well. In an pre-event interview with Recode, Samsung Electronics America president Tim Baxter pointed to this production flaw as the final nail in the Note 7's coffin.
"We believe if not for that manufacturing issue on the ramp [of the replacement battery], the Note 7 would still be on the market," he said.
Samsung Mobile chief DJ Koh said he "deeply" apologized to customers for the company's failures, and added that researchers worked to rule out wired and wireless charging, the phone's USB Type-C port and the iris-scanning feature as potential causes. Meanwhile, TUV Rheinland was also asked to see if the way the batteries were stored or transported could have played a role in the matter, but its response was a pretty definitive "no." In its bid to conclusively determine what happened to the Galaxy Note 7, Samsung also built a standalone testing lab, which it was all too eager to share photos of. They're a testament to how seriously Samsung took the investigation, but really, the damage has been done, and now the question on everyone's minds is what happens next.