There are 4 magnets. The ones on the mini playfield are activated when 'the power' insert is lit and you hit the ball up the right ramp and it goes to the mini playfield. When the pin senses the ball enter past the switch, it disables the flippers and enables the 2 mags in the mini PF for about 20seceonds. You should be able to deflect and bounce the ball around with the flipper buttons.

The 2 magnets on the left and right of the orbit are ready when the spiral insert is lit after just shooting around the orbit for example. The next shot around the spiral will be grabbed by one of the magnets to T-up the ball for the piano shot or camera shot. Those magnets have optos above them. Are those optos working in the switch test in the test menu?

The idea is the magnet grabs the ball when flying around the orbit, so you can get ready with your upper flipper, then it feeds it to you, so the camera and piano shot are easier to make.