Green LED won't light up from circuit.

1 I have a CF (7.01 on the circuit board, is that a 7.5)? with a color expander

2) and my wiring diagram checks out and matches in the saber. But my green LED won't light up.

I can put in the kill switch and put 2 AA batteries on the contacts on the Color Expander connections to the Green LED and get it to light. I can't get it to light up while using the RICE Port to change the color. Does anyone have some ideas on how to track this down? I do have a multimeter but I'm not sure how to isolate the problem. Near as I can tell it can be

1) green + wire to CEX is bad
2) green + wire has a bad solder joint
3) bad electronics on one of the two boards (Defective)
4) fried electronics on one of the two boards (my fault)

You've got the right idea. Try using a multimeter to test the voltage from the colour channel for the green LED on the CF to ground. If there's no voltage, your CF is bad or not configured correctly. If there is, try measuring between the PWM input pad for the green LED on the CEx and ground. If there's no voltage here (but there is for the previous test) your green wire is bad or has a bad joint. If both of these succeed, then you likely have a problem with your CEx.

So I'm showing 1.7 volts on the CF at 950 mA on the green channel (2). That makes it over to the CEx, but 0 volts coming out of the CEx. I would think that's plenty of voltage. In comparison, the red channel (1) shows 2.5 volts at 714 mA.

It sounds like the CEx has a problem, since I'm showing 1.5 volts on the blue channel and it lights up.

Can you confirm this diagnosis please, NanoRex?

The amount of voltage across the pads doesn't really matter; only that there is voltage. I'm not an expert, but it seems to me like there is an issue with your CEx.

We would need to see good, high quality, close up pics of your wiring on the CEX, from the CEX to the CF and on the LED itself.

I can get the LED to light up by applying voltage (AA batteries) to the connectors on the CEX. I'll try to get some closeups of the circuit boards and wiring soon.