Read all this through.. You may want to start with the last-line?
Right.. Referring to this image:
Is this supposed to be a 'special' (built just for you) to do anything non-standard? - There seem to be pull-up/down resistors all over the place, and unless they are to fine-tune actions, then I do not know why this has been done?
Has the calibration process been done on this transmitter? - It should not make too much difference, but removes one query.
(NOTE: If we remove any resistors etc. re-calibrate before testing).
No names, no pack-drill.. Send me a PM, as to who built this please..
Top of picture, there appears to be a pair of 10k resistors which are wired between the two push-buttons? - The right-hand end of the right-hand resistor appears to either be disconnected, or connected to the opposite (ground/black-wire) on the right-hand switch.
Assuming there is a green-wire from each switch? - One to Pin 2, one to Pin 4.
There seems to be a green wire, from this switch, to the centre of these two resistors?
If you look at the circuit diagram:
These switches should have a ground (negative/black) connection, and a 'signal' wire going to either Pin 2 or Pin 4.. - Anything else is not needed, or incorrect.
I would cut the green wire, at the right-hand switch, which runs to the centre of the two resistors.
I would remove these two resistors, and the short bit of green wire, we have freed from the Right-hand switch.
Toggle switch:
The 470 ohm resistor (connected to top pin of switch) should-be (and appears to be) connected to the ground/negative connection of the left-hand push-button.
There should be an 18k resistor from the top-pin to the bottom-pin of the toggle switch. - This appears correct, on the left of the toggle-switch as we look at it.
There should be two 100k resistors. One from the top, to the middle pin, and one from the middle to the bottom pin. - This appears correct.
From the bottom pin of the toggle switch. There should be a 10k resistor to the red wire going to a pin on the edge of the Tx2 module.
There should also be a 10k resistor, from the right-hand pin of the Speed pot. going back to this pin. - The resistor appears to be in heat-shrink near the connection to the pot. and this wire seems to join correctly to that from the toggle-switch.
Speed control:
I assume the left-hand end is wired (very firmly) to the bottom row of pins of the Tx2 module, and it is this holding it in place?
Right-hand pin we covered, above.
Centre-pin (yellow wire) should go to Pin 1. - This appears correct. There should not be anything else connected to Pin 1.
Whilst we are talking 'yellow wires'.. There appears to be a yellow wire, from the negative (bottom row of pins on the Tx2) going 'somewhere'. - Where does this go?
Bind button:
Should have a ground/negative/black connection, and the white wire to Pin 5. - Appears correct, and you must have bound a Rx to the transmitter.
'Signal' pins on the Tx2 module:
No signal pin (top row of pins) should have more than ONE wire connected.
Battery positive:
This should be wired directly to any of the centre-row of pins. - There should only be ONE connection to the centre-row of pins.
Other 'extra' resistors:
Other than those we have talked about, there appears to be a resistor in the black lead from the Tx2 to the left-hand push-button??
There appears to be a resistor in the black wire continuing from the push-button?? - You can see it below the junction of the two top resistors and the green wire, top-centre of the picture.
From the circuit diagram, there are NO resistors in series along the negative connection between the switches.. - These should be plain-wire connections.
Alternatively:
You may wish to send it to me, and cross my palm with silver?

PhilP.