I only do this once in a blue moon and seems like I cannot get it to stick.
IoHD is connected to the Mac, open the Io CP, make all the setting, this last time I need to send a 16:9 image from a camera to a TV as letterboxed. Got it all set up as needed, Video on TV was correct.
Coming in Analog Composite - video 16:9 out of a HVX
Going out: Analog set to Secondary (since that is where the Letterboxing is done)
Then go to Control tav.
Default Video Output: Input Passthrough
IoHD Stand Alone Mode
IoHD Display Mode
Primary and Secondary
Hit burn, remove FW cable from Mac and all is well.
Then if I have to restart the IoHD I just get the color bar pattern. But if I just connect the FW cable back to the mac and open the AJA CP it works fine and then I can disconnect the FW cable as it keeps on working.
Not a big deal most of the time but I would like it to stick.