And the other switches on that row do register, right?
Just a comment, physical switch connections will almost never match the order of switches as shown in the schematic. Switch matrix (and other) wiring is routed to minimize wire required.
Some switches in a row working but others in that same row not working rules out the MPU board and the connection to the board, assuming all switches come in at the same connector (i.e. all on PF or in cabinet.
This leaves only a few possibilities in this approximate order of probability.
1. Broken daisy chain between switches. Buzz from switch solder tab to all others in the daisy chain.
2. Failed switch. Clean the gold flashed contacts but pinching a business card between them and pulling it through. Meter for continuity when closed.
3. Failed 1N270 germanium diode or solder joint on the diode board. Remove the connector. Examine solder joints. Diode year with a meter. Should be open one way and about .220 the other way IIRC.
4. Failed IDC connection at diode board.
Multiple switch failures are almost always a break in the daisy chain.
Happy hunting soldier!
Chris Hibler - CARGPB #31
http://www.PinWiki.com/ - The new place for pinball repair info