Let me know which model remote you have--it cuts down on the guess work.

Anyway, assuming you have an Atlas or Cox remote, try 07044 or 07042 for Power On, and 06980 or 07010 for Off.

I got most of these codes at hifi-remote.com, using the free software RemoteMaster.  The LookUp tool (link shown at top of each page at hifi-remote.com) is pretty helpful to see what the various setup codes send.  For the LG TV, the IR codes are listed near the end of the manual.  Use RM to convert these into EFCs that you can enter into the remote.