I do have a meter
First w need to start at power source. Some furnaces have humidifier terminals that only hot when the gas valve is energized. What furnace do you have? Or do you know if your source is hot and when?
That is a 24 volt terminal from circuit board.
You will need to go to point of power origination. Remove wires from HUM terminalsand measure voltage there.
It is either miswired or came apart. Check HUM to terminal C for 24 volts during the furnace cycle. Once again HUM is 24v hot only while the gas valve is energized.
From hum the 24v goes to one side of humidistat, out the side of humidistat to one side humidifier, out humidifier and back to common.
once i connected the lead to the terminal on the circuit board, the solenoid opened and began working during a heating cycle. thanks.
Excellent. I am glad it worked for you.
I would be more proud if I fixed it but you beat you me to it...well done!