I ran into a small issue / fix this week that might help GB owners who are 1st time owners.
My GB-Premium is a whole year old this month.
Recently I've noticed the left scoop was waiting a while (and taking longer) to kick out the ball.
This morning the ball just sat in there as if nothing happened and then the machine went into ball-search.
I shut off the machine and found the switch in the left scoop was squashed down so it barely was being pressed by the ball.
If this happens to you....
With the glass off and the power off, put your finger in the scoop and feel for the switch.
Gently bend the tip of the switch actuator back upward toward the playfield surface.
I tested with power off listening for the click to ensure the click happened before the switch bottomed out.
Next - Test it in switch test mode with a ball.
Caution: The solenoid will fire if you use your finger to press the switch wacking your finger so turning off the machine is advised.
Now The response time is back to what it should be.
The moment the ball lands in the scoop the flasher goes off and kicks the ball back up.