There are E field amp 2 traces... just no signals. Let's do some 'eyeball' and 'mechanical' T-shooting:
You have red and green LEDs only lit on the E amplifier? Green lit on the Preamp? (It is very dim, however... This LED is used as a rail-splitter for the op amp... 2.5V up on pin 3.
Probe connected to preamp inboard antenna block, not outboard? Shielded CAT to controller?
Disconnect H field amp. Run E field controller 2 only...
Bring gains up on E field... anything?
Swap E field to controller 1.
Anything?
Redundant, in a way, but Swap H field to controller input 2, make sure controller's good.
Reconnect E to controller 2, H to controller 1.
That's gets you back to original setup.
Now, assuming good E CAT cable...any doubt, try another.
----------got to this point... arrrgh--- now, move on ---
If no signals at all, correct lights lit everywhere, good cables, etc.
Problem either in Preamp, Connectors, or limited devices in amplifier.
1. Make sure the ICs are installed correctly. Tiny pin 1 dots hard to see... esp Preamp IC1
2. Check all solder connections on SMD's for bridges or bad.
3. Check connector pins preamp probe. Some have broken the pin where it runs through board.
4. Make sure all components are right value, right polarity... easy to confuse a 6.8M with a 68M, e.g.
5. Make sure solder connections RJ45 good both amp and pre-amp.
6. Look at Amp schematic.... problems probably not in any of the ch output ics... no signals getting out... problem in common amps all channels, or in preamp.
None of the above... step back, scream once... stare at it... scream and curse if necessary.... then start checking voltages and break out oscope, etc.