Pinball machines do not have playfield schematics per se. All the playfield connections are laid out by the colored wires specified in the Solenoid Table, the Lamp Matrix Table, and the Switch Matrix Table. You should have all these tables in the manual you downloaded. If not, download the copy at ipdb.org.
I agree with zacaj that your problem seems to be a switch matrix issue involving the tilt switch. Switch matrix issues can be a bear to isolate, but they're easier to figure out if you have some idea what you are working with. There is a good article explaining how the switch matrix works and how to troubleshoot it at pinballrehab.com.