Hello. Just got a Stargate myself and have a similar problem to your left kicking rubber. My center and right kicker targets don't work during the game, but test fine during a solenoid test, and the switch test shows them as constantly closed. I looked and none of them were closed. I did realize target kicker switch does work because it resets the drop targets when struck (but no kicking or scoring). So I called the pinball resource, inquiring if the switches were available (thinking short). He said it didn't sound like a switch problem to him (six switches -two inoperative and four stuck closed- failed the game's test) and to check the switch matrix. He said the computer remembers that the switch closed but nothing is telling it that it has opened back up so any further input is ignored by the system. In short, check the switch matrix column where the switch appears (pg 50-51 in the manual) for loose wires (both before and after the switch in question). Also check if the other switches (glider forward - left return rollover - left kicking rubber) are in the same matrix. If so, one fix to the faulty part of the matrix may help restore function to them all. I will get to work on mine later and will let you know if I find anything that can help.

Got back late last night but checked the switch matrix diagram. It looks like left kicking rubber, right flipper, pyramid end of stroke, and left return rollover are all in the same matrix. Seems too coincidental. I'd scour that matrix if i were you. Check the diagram column three beginning with #3 coin chute and work down from there. Good Luck