1. Background
From the recent market feedbacks, part of R821 machines mainboard cannot repaired by version upgrade for the reason of software, and needed to be replaced by a new one, which caused increasingly high rate of board replacement. By analysis of development and quality department, it was estimated that the fault was possibly caused by EMMC defect. Due to the high price of mainboard, it caused a high rate of giving up repair of those users whose machines were out of warranty, which severely affected customer satisfaction. For the situation from above, it is necessary to adjust the repair price of R821 mainboard.