This is LG GPAD test mode I found from other website.
How to access the LG Gpad 8.3 (LG V500) Hidden Menu?
1) From Home screen,Touch the “ Contact”
2) Touch the “ Search Contact
3) You can see the “Keyboard” after Touch the “ Search Contact”
4) Touch the “+ “ icon after Dialer 3845#*500#
Now you can select the “Device Test” and then Select “All Auto Test-Full”