Have you tried the manual?

When switching from Mix/Tape mode the inputs to the faders will switch from mic/line to tape return.
The large and small faders will switch duties....IE: Channel fader and Monitor fader

Some other things will switch but it's console dependant and not knowing the specifics of that console I can't go into it.

Might wanna try gearslutz.com.......there's some trident owners ther.

Thanks.

The only manual that came with the desk is a flow diagram type thing which is only partially helpful. I'll give your suggestion a try.