If some of the buttons are working but not all then this device working but it needs proper keymap. Android maintains keylayout or maps at /system/usr/keylayout
There it stores files in vendor_id_product_id.kl format. So you need to download minix neo A2 lite key layout. I have already googled for you, you can download it from their http://minix.com.hk/downfile/Vendor_...roduct_107a.kl
Now upload that file to /system/usr/keylayaout
But remember, you need to make sure your device is root and /system is mounted rw .
If you device is root then through some shell emulator program , do following :
To get super user permission
Code:
mount -o remount,rw /system
To give write permission to /system.
Now copy that file and restart your system. If everything goes good, all buttons should be working by now.