1. Wiggle the ribbon cable feeding the display. I had to replace mine (after I had already bought an LED replacement), and even then the next owner had to replace it again (something about the reach of the cable)

2. Check the matrix, both coils might be on the same line. Another user here had a short issue where the upper left solenoid in the gobble hole would fire at the same time as the trough solenoid.

3. Bottom right board I assume you're talking about the GI relay? It should only click when it's adjusting the GI (lights turn off usually at the end of a ball).

Have you measured at the connector for power?

Check your test points on the power supply for correct voltages. Sounds like The power supply needs work in the 100+ volt section or get a new set of led displays and you will not have to fix the 100 volt section of the power supply as the led display only needs +5 volts to operate, witch eliminates the use of the 100 volts on the PS. This is a common issue on system 11 games. Or you could go with a new rottendog PS for around 100.00 the led displays are a little more or have your original PS fixed, It will cost around 100.00.

for the 2 coils for the ball eject. Check the colors of wires. Do they share a color? If they do follow that color farther upstream. you might have one wire off upstream of the daisy chain.

Check, Check & recheck! Check all your needed voltages including the test points on the board. Rebuilding the power supply is easiest thing, and cheapest thing to do. Start with your voltages coming up from your transformer. Unplug the male/female plugs in the base cabinet of your transformer that send the voltages up to the backbox, check all required voltages on the transformer side, plug back in and recheck all voltages at their destinations. If those are correct check your power supply board voltage outputs. I rebuild all my boards. You still might need a displays.
Did you go through a manual diagnostics to see what coils do and do not work?