I have a Gottlieb Monte Carlo with clean boards that boots and will play if I move the ball out of the trough outhole but there is a full row of switches that won’t register (strobe 6: #2 #4 #7 #9 drop targets, left return rollover, trough outhole) . In test mode with pinballs removed, all switches show open. Is this a board issue? (one of the Z chips) or should I be looking for something else like connector, wire continuity, under playfield wire, diode board etc? Thanks I’m not familiar with the 80B boards. I don’t have a scope. Is there a certain Z Chip associated with this switch matrix row that I can try to change? I don’t see any broken wires associated with any of these switches. Any help would be appreciated thanks.
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Thanks @chrishibler, with the board removed I used diode test on my meter on Z11 and some legs of that chip are reading .184 and others are .526. One leg (2nd down from top left) is reading “0”. I’ll try replacing the 7404 at z11.

Thanks @chrishibler, I removed z11 and socketed in a new 7404 and everything works great!