There are two windings on the coil. The high resistance winding and low resistance. If you look carefully at the flipper coil the low resistance winding has thicker wires. The high resistance winding should be wired to an EOS switch on the flipper assembly. That switch is normally closed. If the EOS is not making contact the flipper will not flip without help.
First check thwe EOS on the upper flipper and make sure it's closed and not opening until the flipper is about 75% flipped.
Second, take a clip lead and tie it the grounded frame of the game. One side of the coil has a brown wire providing 43v, touch the lead to the the other side of the low resistance(thicker wire). That should fire the coil. If the coil does not fire its either:
A. A bad coil,
B. No 43v on the brown wire