'77 Zenith ChromacolorII SC600 remote

[Adam]

What remote does it use?

It's the 17JC55 chassis, the manual says it uses a SC600 remote. But with every SC600 remote I have, channel up and down works, off/on steps the volume up and down, the volume button is mute, and no button will turn it on/off. I tried all the other remotes I have, and the channel down button on a RCA mechanical remote from a '61 B&W TV will turn it on and off, so I don't think there is anything wrong with this tv, but that I just have the wrong remote. I'm thinking that maybe this uses one of those electronic ultrasonic remotes that Zenith used in the late-70's and early-80's (I don't have one to test). Because if each of the 4 buttons on a mechanical SC600 remote perform a different function and none of them turn it on/off, and a different frequency on another remote does turn it on/off (and does nothing else) it seems like this would have to use a 5 button remote.