Got a Mattel Las Vegas (1978) pin as my first DIY repair/restore project. Ultimately want it for my kids to play. Game was stored indoors and not "turned on" for several years. It is in excellent physical condition with no dents, scrapes or playfield wear. It powers up, lights up, but it will not keep score (targets, roll overs, bumpers, sling shots, rebounds do not register points).
I have owner and service manuals, but I am no electrician. Seek guidance from anyone that may have worked on a Las Vegas and on "where" to look first to address score issue.