Download latest Android Jelly Bean 4.1.1 stock firmware for JXD S602b game pad from here or here. Download anothe JXD firmware from here.
Archive: S602B-JXD-V3.3.8-20130731H_SD
Model: JXD S602b game pad
Image: u-boot-5110b-v4.2.0.bin
Image file size: 258 MB
Platform: Amlogic MX-LBuild number: softwin-user 4.1.1 S602b 01-V3.3.8-20130729 test-keys