"Slightly" energized coils are a common problem in System 80 games. It is due to grounding problems, that cause the solenoid driver transistors to stay a little bit conducting and the infamous burnt driver board.

See https://www.flippers.com/gottlieb_ground_cures.html

If the solenoids release when you turn power off, then it is not a problem of magnetized coilstops or plungers. Anyway a good point from frunch, they sometimes really do get magnetized enough to prevent solenoid release.

For the grounds, the idea is to make sure that all grounds are tightly connected to each other and at the same potential. Most importantly, the solenoid ground and logic ground.

To make sure regulator frame is properly grounded, connect a (thick) wire between the upper (-) leg of filter capacitor and frame, as explained in this picture from flippers.com page.
Gott-Sys80-Reg-Gnd_Mod (resized).jpg

Then check that all other ground points (including cabinet ground) do not differ more than 0.2 volts from the regulator frame. If you see a voltage difference, tie the corresponding ground point to the frame. This assures there are no ground differences that could keep the driver transistors partially connecting.

Great to hear you got it working!

And also thanks to John at flippers.com for the picture and instructions.