Hello, glyn,
Addams will have a special 'Flipper coil test' incorporated into the test routines. Get into Test Menu, then step through to the Flipper Test section. Each winding of each coil can be pulsed individually, so select the lower right flipper - I think the primary (power) winding comes up first. Then select the 'hold' winding, which seems to be the problem here. The test pulse should be able to move the flipper paddle, but only weakly, since the power winding does most of the work in actually flipping the flipper.
If the hold winding isn't working, the Start button calls up help information, such as wire colours, connector pins, and driver transistor number.
As mentioned above, the most likely cause is a broken hold winding in/on the coil. If you're careful, it's possible to by-pass all the Fliptronic driver stuff, and check the coil by grounding the correct terminal (for the hold winding, in this case). Disconnect the wiring connector for the coil returns from the Fliptronic board first, then simply take a jumper wire and connect one end to the grounding braid running around the inside of the cabinet. Identify the hold winding terminal, AIR it's furthest from the 'live' terminal, which mustn't be grounded. Then touch the free end of the jumper to the hold terminal, which should energise the winding. With the power winding the circuit should only be made briefly, but the hold winding is meant to remain On so you can clip the wire in place on the terminal.
