I just finished my Stargate that had the playfield repaired and clear coated. Had a tonne of faults.
In multiball modes the ball would auto plunge out and stick behind the drop target this was due to the plunger spring on the outside the cab being shorter due to wear and the ball not sitting correctly on the lane switch also make sure the switch contact line up properly as in the faces line up for the best contact.
I couldn't navigate diagnosics with the flipper buttons I had two shorted pop bumper coils replaced both had to replace the blown transistors and fuses along with a blown sling transistor. After I had repaired these coil problems I was able to use the flippers to use diagnosics.
Now i'm trying to get the flippers a bit more snap replaced the eos switched and sleeves coil stops and there better but still want more and ideas would be welcomed will be looking at new flipper button switchs maybe.