Samsung had a good start to the quarter, but the battery problem that caused some Galaxy Note 7 smartphones to catch fire led to lower sales of the company's high-end and high-profile line of Note products. Samsung's smartphone sales in the Q3 as a whole declined 14.2% year-on-year, their worst performance ever. Samsung's previous worst performance for smartphone sales was a 12.3% drop in the Q4 of 2014.