Thank you for your reply. I tried the Harmony universal remote and also the IR remote app on Samsung Galaxy tab. Nothing worked out. Now my TV is stuck in Factory mode. The message floating on TV says, Press INSTOP to go back to user mode. I have tried LG service remote, Harmony remote and Samsung IR smart app to send INSTOP command. There is nothing happens.
I also tried the P-only button on service remote that allows to enter the Instop without password. When i press P-only button, the TV turns on with message saying pressure exit and turn-off to exit P-only mode. Press Exit and INSTOP