Can the resistor the zex n20 kit go bad?

Holy crap I keep having problems!!! My n20 worked fine last night then I got home shut the bottle "i did not purge the line”. This morning I remembered I didn’t purge the line so I went KOEO and went WOT but the solenoid did not open.

This happened once before and then all of a sudden worked great again.
All of the wiring is correct and it all reads the right voltage.

If the throttle is WO and I put power to the n20 box I will hear a really high-pitched hum "like a camera before a flash". However nothing will happen if the kit is armed and then i go full throttle.
For some reason the solenoid will not open. This is a zex dry kit can anybody help me??

damn i have posted problems with my n2o like three other times and nobody replys. WTF?

Thank you notchback for your reply. it is appreciated.

The kit i bought used. I do not know if their is a green light or not. The kit is well hidden. The box and all of the wires are mounted in the cowl vent and the only line that gose into the engien bay is the intake tube feed line disguised as wire harness.... (What nitrous) lol.

I have also had the same problem as you once before could have easily blown my motor had i not shut it off.

where is the green light on the box?
What did you do to fix the problem?