The key statement here is "start a game". If the solenoid immediately energizes when the game is powered on then it is more likely to be the drive transistor (or the pre-drive transistor or the digital logic output pin driving the pre-drive transistor). If the solenoid only energizes when the a game is started (or you enter diagnostics) then it is more likely to be the special solenoid trigger (playfield switch). There is a signal (EN) that disables the special solenoid triggers when the game is not active (or not in diagnostics).

More information. Good.

The special solenoids energize when the corresponding special solenoid trigger (playfield switch) closes. These switches are ORG-XXX wires on the supply side and (typically) WHT on the ground side. If you have continuity between the ORG-RED and GND then check the physical trigger (playfield) switch. If the leaves are not in contact then pull 1J18 from the board and check for continuity between the ORG-RED and WHT wires (in the connector). If you have continuity go back and look at the playfield wiring or the switch leaves. If you lose continuity (in the connector) then check for continuity between the corresponding pin (in 1J18) for ORG-RED and GND.

"Shotgunning" or guessing is generally not a good way to diagnose the cause of a problem. I would wager that changing the drive transistor does not help in this scenario because there is not enough evidence to indicate the drive transistor is the cause.

So to confirm ... with the board isolated you have continuity between 1J18-3 and GND (any point connected to the ground plane)?

If so there isn't a lot connects to 1J18-3.

sst2.jpg

C57 is indicated as red in the diagram because you say that there is no continuity (tests open). This is expected and correct.

The only other place that is connected is U7-5. You can check that is continuous with GND. It's likely you have a bad 7402 at U7 and you will need to replace that IC.

Test the other capacitors there. They should all test the same = no continuity. This is just verification that there is indeed a difference in the SST2 circuit.

Unfortunately, you can't tell if the capacitor is bad or if U7 is bad. The continuity to GND could be through the capacitor or through the IC. Capacitors rarely go bad but it's a simple and cheap component to replace if you want to check. You can also cut the leg not connected to GND, lift it out and re-test actual continuity through the capacitor (measure from the cut lead to GND). If continuity is shown the capacitor is bad. Otherwise test continuity from the pad of the cut leg to GND. If there is continuity then the path to GND is through U7. In this case you will need to replace U7.

That is Texas Instruments SN7402N. You can search for "7402". Do NOT use 74LS02.

This is NOT an endorsement of any merchant. The order of the listed merchants is also not an endorsement or should not be considered preference.

• https://www.marcospecialties.com/pinball-parts/7402
• https://www.digikey.com/en/products/detail/texas-instruments/SN7402N/1575110
• https://www.mouser.com/ProductDetail/Texas-Instruments/SN7402N?qs=QViXGNcIEAuGgIUBg6L9Pw%3D%3D
• https://www.newark.com/texas-instruments/sn7402n/ic-logic-74-nor-gate/dp/64AH8747

And probably a bunch of other merchants as well.

I will go out on a limb here and say that the mylar installed on the recent images of the Space Shuttle playfield is not factory.

shuttle.jpg

• red arrow show factory mylar ring for pop bumper skirts
• gold arrows show "hand cut" edges of non-standard "mylar"
• gold rectangle shows "free form" edge cuts around the drop target

Factory cuts are typically computer generated. The arcs are perfect. The spacing is regular and consistent. Hand cut (after market) "mylar" shows all the hallmarks visible in this image. Don't believe me? Look at some other System 11 machines (I know this is a System 9 machine) with factory mylar. You will see beautifully cut, smooth edges.