It reportedly took three quality-control companies to find the issues.
The mystery of why Samsung's Note 7 phones kept exploding might finally be solved.
The company is planning to reveal the results of its investigation into the faulty devices this weekend, and according to a Wall Street Journal report, it's going to blame two separate battery issues.
First up is that some Note 7 batteries were "irregularly sized", leading them to overheat and explode. That led Samsung to recall its first batch of devices.
The problems didn't stop there. Samsung stepped up phone production to make up for the Note 7 shortfall but, according to the report, that resulted in more problems. This time, the batteries had an unspecified manufacturing issues that again caused the phones to explode, leading Samsung to issue its full recall in October.
It's reportedly taken three quality-control and supply chain analysis firms to reach this conclusion, with Samsung set to blame the manufacturing partners responsible for its batteries.
A Samsung affiliate, Samsung SDI, was reportedly responsible for the first set of faulty batteries. The second batch was supplied by Hong Kong's Amperex Technology Ltd.
Samsung apparently plans to step up its testing and inspections to stop the problem from happening again.
The company is separately battling its own domestic scandal, with group chief Jay Y. Lee embroiled in allegations of political corruption. He was questioned this week over alleged bribery and has denied the accusations.