Radio help

[Snowman 78]

Can a radio lose a channel?

I have a 3PM, I wanted to use it in my CRT.5. I hooked everything up and the steering servo would not work. (I though I had a bed receiver) so I got a new receive and I am having the same problem. Channel 1 on both receives do not work. I am using a new servo and a RX pack to do the testing. When I hook the servo to channel 2 or 3 it works fine (with each receiver) but channel 1 won’t work. I check all the setting on the radio and they are good.

Thanks for your help.