gamit kopo cm2 dongle
firmware with password:http://www.mediafire.com/file/58c1e86w4vnkkvv/Oppo_R831K_11_A.10_140911_MTK6572_4.2.zip
firmware with password:http://www.mediafire.com/file/58c1e86w4vnkkvv/Oppo_R831K_11_A.10_140911_MTK6572_4.2.zip