I have an Onkyo 828 and when I used the AV Producer 8 in 1 remote, all I have to do is hit the number 2 to get video 1 or the number 3 and get video 2 or the number 4 to get video 3, etc. try that, it might work on the 939.

Just set the remote for tuner and select the correct code for you onkyo 939 and then using the numeric keypad send a 3 and see if it switches to video 2.

Tim Huey