You have one of the rare machines controlled by Skynet.

Hahahaha,nice sealclubber!!

Have this Pin also and its rad,my high score is 330million and it took 5 superjackpots to get it!! Sorry i cant help with the technicalities as im absolutely hopeless in this area but im sure someone on here will soon have some good advice

I'm pretty certain the cannon shouldn't start until the ball enters it and triggers the switch in the barrel. Check that switch in test mode to make sure its not stuck on first. Let us know if that works.

I had a look here and it sounds like a similar problem, maybe somewhere to start looking for a fix.

http://groups.google.co.uk/group/rec.games.pinball/browse_thread/thread/963c9fa19344a989/183a4f5f02df9357?hl=en&ie=UTF-8&q=terminator+2+pinball+cannon+problems

This is an old and wellknown problem.
it's caused by a broken wire in the loom to the gun's opto's

This causes the opto NOT to "see the light"
The game thinks the beam is interrupted by a ball in the barrel and tries
shooting it.

In gun test you may find no problem at all cause this is a typical
intermittent problem that only occurs in certain rotation positions of the
gun, may even only happen during movement.

Replace the entire gun harness,

Nice info Bugray
the game I play at the local pub has the same gun issues
maybe thats why no one ever plays it?

i just put some mods on termintor 2 went i start using gun cannon now goes real fasters i have taking mods out it stall does this anyone can help