Clean the rollover switch contact with a business card and make sure the contacts are close enough together to make good contact

Reseat all the display connectors going into the main display board (with the credits on it), see if that effects it at all. If not, try swapping good and bad displays around and see if the problem stays with the display or with the player number, that'll tell you if it's a problem with an individual display or with the master display

Also, re-seat the connectors that run across the top of the CPU board. Only re-seat cables with the power OFF.

If this resolves the issue, you should replace the header pins on the CPU board and possibly replace the cable connectors. Re-seating the cable is usually a temporary fix. Replacing the header pins might should make it reliable.

As for the rollover switch issue, Williams had a lot of improperly assembled switches. One contact was installed wrong. The switch can be disassembled and the blade flipped, but the other contact may be damaged and need replacement. Pinball Resource has all the parts to rebuild switches.

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