When I enter more than 1 player on my Williams High Speed game the following happens.

Push once for 1 Player: Everything normal.
Push again for 2 Player: Back display flashes "Ramp Bonus 50,000" then spots player one 61,610 points, followed by 2 clicks from the right hideout solenoid.
Push again for 3 Player: Back display again flashes "Ramp Bonus 50,000" then spots player one 139,220 points, followed by another 2 clicks from the right hideout solenoid.

I have gone through and checked every diode in the switch matrix and found no issues (only exception is the Center Coin Chute, which I don't believe I have on my machine). Each diode reads approx. .58v drop in one direction and .OL in the other on my DMM set to diode setting. All diodes are facing the correct direction and are securely soldered.

When I go into Switch Edge Test and manually activate each switch separately the display does shows the correct switch each time except when I push the Credit button (#03) and Right Coin Chute (#04). When I activate those separately the display shows "Upper Left Star" (#51) for some reason. The "Upper Left Star" works just fine and everything appears okay with it.

When I go into Switch Level (05) in diagnostics and cycle through the switches using the Credit button I get the following on the display.

1) First Push: #03 "Credit Button"
2) Second Push: #51 "U Left Star"
3) Third Push: #43 "Right Ramp"
4) Forth Push: #35 "R Jet Bumper"
5) Fifth Push: #27 "Target Arrow"
6) Sixth Push: #19 "UL Bank Green"
7) Seventh Push: #11 "Center Trough"

These happen to be the 7 switches on row #3 of the switch matrix. It seems odd and could be an indication of where the issue is but not sure.

Any assistance would be greatly appreciated. This have me scratching my head.
P1 (resized).jpgRB (resized).jpgP2 (resized).jpgRB (resized).jpgP3 (resized).jpg

Figured this one out on my own. Turned out to be the Slam Switch. It was grounded out. Simple bending and problem resolved.