Quoted from Quench:
Yes, that's the procedure. Which part(s) don't you understand? (so I can make it more clear)
Can you post some pictures showing the wire connections on all the drop targets and the outlane switches?
Oh please post a clear picture of the J2 connector on the MPU board so I can see each of the wire colors and where they're positioned.
Can you lastly clarify if switch test mode reports "0" in the Ball in Play display when no switches are closed (i.e. all drop targets are raised and the ball removed from the machine)?
Connectors photos linked. Note, the soldering ain't beautiful because I had disconnected the diodes to test them and then resoldered. Also on the left upper drops I added some wire extensions to the solenoids because two of the wires to the solenoid were too short. Even though it may look like it in the photos none of the switch connections are shorted, but if better photos will help please let me know what you would like to see. https://photos.app.goo.gl/Rt4tNexfRpeRVHBu7
As to testing the switches, yes the Ball In Play shows a 0 (zero) when no switches are closed. What I don't understand is how the MPU can show switch numbers 1, 3, 5 for three of the drop targets when there are no such switch numbers? And why does the right outlane register as #7 and the left as #8? All the other switches register correctly. Here are the colors of the wires in the J2: (photos not always as easy to see colors)
1) white-red stripe
2) brown-white squares
3) white-blue stripe
4) white-yellow squares
5) yellow-red stripe
7) not in use
8) dark brown (goes to lower drop target)
9) gray (goes to top left outside drop target)
13)white- brown stripe
I know that some of these colors do not match the schematic/matrix. A) J2-2 is supposed to be Gray-Yellow (there is no gray and yellow wire in my game) but in my game they used a light brown (tan) with white squares that goes to both saucers, the 4 bonus advance rollovers. Those switches behave correctly and score correctly.
B) The lower left drop target on J2-8 is supposed to be white and green, but the original looking pin connector and wire laced through the wiring bundle is the dark brown wire.
C) J2-9 is supposed to be white-brown, but in my game a grey wire goes to left top outside drop target and sure looks original
D) J2-12 is supposed to be a brown wire, but a white-green wire goes to the top saucer, the four 10 points switches, the right top outside drop target and the left slingshot. The drop target is supposed to be #29, but shows as 05.
E) J2-13 is supposed to be brown-yellow but in my game it is a brown wire with a white stripe and goes to the bonus rollovers, 50 points switches, spinner, bottom bumper. These switches score correctly.
F) J2-14 is supposed to be brown-white, but in my game it is brown-yellow blocks. That wire goes to the tilt, right inlane, right outlane, right bumper. The right outlane registers tilt and fires the right bumper, but does not actually tilt the game (does not skip a ball in play)
To make sure there is nothing wrong with J3 wire order here is how they are set up:
2) red-yellow blocks
3) red-green blocks
4, 5, 6, 7, 8 not used
10) brown-white blocks
12, 13 not used
14) blue-white blocks
15) blue-orange stripe
I have heard from other sources that the early Stern schematics did not always match how the game had been wired. So even though the colors may not match I have traced where the wires go. It does seem strange that 3 of the drop targets are not using return wire colors as are listed in the schematic, and maybe how those wires are being used is a key to the problem. The fact that J2-8 and J2-12 have their wire colors switched is interesting but then why is there a brown wire from J2-8 that only goes to the lower drop target?