Some says AIO-3399J cannot connect adb , this post for this problem.
Update Firmware below to fix it.
1.fixup AIO-3399j adb connect.
2.fixup some problem about video decoding. 3.connect to PC add a memery status.
4.support ordinary driver about usb2uart.
5.fixup the virtual keyboard always showup after insert the physical one.
Firmware Download
If do not overwrite the system image , can download the patch to fix it
drmservice.rar (10.8 KB)
drmservice.rar (10.8 KB)
Copy the patch file under /system/bin/ from your UDisk with usb2uart module or some file explorer to do it (root will be needed), and soft reboot end
Serial Command to do:
su
mount -o rw,remount /system
cp /mnt/media_rw/U-Disk/drmservice /system/bin/
reboot