This is a tough one.
Basically, there isn't any way to make the flipper coils too strong, without something really strange happening in the power circuit.
Here is a link to the manual for your game:
On manual page 88 (page 102 in the pdf)
You can see that AC power comes in to the IO power driver board on J11, pins 2 and 3. Measure AC voltage there, one probe lead on pin 2 one probe lead on pin 3, and you should get something like 56V (48V, plus a little). When I measure DC voltage from the metal ground plate to the top of Fuse 21, I get 78.8V DC. I measure this with the black meter lead touching the metal backplate, the red meter lead touching the top of F21, with the meter set to read DC Volts.
Open the coin door, pull out the little white nub on the left side that is the safety interlock. Reach inside the coin door, and put your black meter lead on the metal box on the right side. Put your red meter lead on any flipper coil terminal. They should all read alike, and on my pinball they read 78.8VDC.
Q15, and Q16 run the flippers. But all they do is connect ground, to complete the circuit. They can't fail in a way that makes the flipper stronger. The only thing that makes a flipper stronger is too much power.
So, in the manual on page 95 (pdf page 108) is the big 9-pin plug going to the power transformer. Your game should be wired for 115 Volts. It's possible that someone had this game in a low power environment, and had rewired this plug as they show on the bottom left corner of this page where it says 'Configuration for Japan or Low Line Voltage'.
If that were the case, I'd expect the flipper voltage to be higher than 78VDC! And the flipper to be too powerful!
So, report back to us on what voltage you measure, and if it's reading too high, look at the power transformer plug in the bottom of the game and make sure it's wired as it shows in the manual "Configuration for Domestic 115V'.
As for the soft settings... put those back to factory default.
Let us know what you find!
Quincy, FL
