As the fuse burns, you could not test any voltage but only test wire resistance with an Ohmmeter with pinball powered off...
20Volts are for motors so unsold the chopper motor and test his ohm value, if you find 1 on there legs, it is burned. Follow all green grey grey wires 588 and test any things sold on those wires.
Also check C2 and the diode bridge links to F6 as show on schematic.
Ps: this is a Stargate schematic so you'd better check if wires colors are same

Good luck
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If flippers works on test mode but didn't in plays, it came from a cold solder wreck on common wire number 288...as the F30 is also link to this common wire, it probably be broke somewhere

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Follow wire 288

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Look at the card powered optical switches fix under the playfield, if a red diode shines, optical sensors are bad. 1 red diode for 2 optical sensor, pull off connector and clean them then retry...(was the problem on mine) To work on optimal switches, use a camera or a phone camera when pinball powered on...the transmitter might look brighter (like a diode shining but lower) to be sure that it came from the transmitter, switch the bad one with a one working...if it works it came from the card, if not you have to change the transmitter. If the diode works but nothing happen when you pass through, transmitter and receptor might be align better.
Good luck

1st check continuity to ground wires then test if you got 5volts coming to the optical card board...

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