Transistor legs to and including coil are good. Doesn't mean transistor is good.

LTG : )

Test it in the machine.

Only one wire will go to 1J18 pin 8, the other should be a jumper from another switch.

You can test the pia, nor, predriver and driver in circuit under power and under load in the machine.

Transistor testing in the System 11 tech pages, section 3b http://techniek.flipperwinkel.nl/wms11/index1.html

I would connect a logic probe and put the game in coil test and lock it on solenoid 21. I would then check the inputs of U-50 for this circuit. Pin 3 should be low in test. Pin 2 should be high with low pulses from the pia chip. Then check the output pin 1, it should be low with high pulses. Next check the base (middle leg) of Q-76, if U-50 output was good then there should be a low with high pulses on the base of the predriver. If all this is good then check the base (left leg) of the Driver Q-77. It should be low with high pulses if the predriver is working correctly. With a DMM set to DC volts one lead on ground and the other lead on the collector (middle leg) of Q-77 you should see coil voltage (34 volts) and then zero when its pulsed.

A logic probe is not required. I do all these tests with digital multimeter. As far as the switches are concerned, the one that registers in test is a scoring switch only. The spoon switch that activates the coil is connected this way, diagram from the tech pages

sketch-1524406357161.png

You can check any of the logic with a DMM. I've never owned a logic probe and only bring out the oscilloscope for audio and timing troubleshooting. I've been in electronics for over 30 years. Use the TTL voltage equivalents below.

Read the tech docs at the link to learn how the special,solenoid circuits function. The diode on the coil is a flyback diode to protect upstream circuitry. If it is bad, it could have taken out the driver transistor and more. The transistor on the MPU? Which do you speak of? There's a transistor for your switch matrix, but if that was out more switches would not work. There's a predriver along with the driver, both of those need to work to drive the coil.
What you need to diagnose is to follow the pulse train through the special solenoid circuit to see where that is getting lost at.

04312 (resized).png

The diodes are mounted on the aux power driver, so there is no need for a diode on the coil (it won't hurt anything. Unless it shorts) The lower pop picks up flyback diode D20 at 5J3-2. Diodes were moved off the coils to reduce chance of breakage from coil vibration in later system 11 games.

How do you know what to replace, or are you just shotgun replacing randomly? If you look at the link to the tech docs, there is a diagram of where you should be seeing pulses in the special solenoid circuit. Once you have some idea of where the signal is lost, you'll have a better idea of what to troubleshoot.

s11ssol1 (resized).png

In your first post you said the switch closest to the spoon did not register in test or game mode...from what you just said now, shorting that switch fires the coil. Do I have that correct? ,If that is true, then the spoon switch is faulty.

If the game still does not fire the coil in test mode, but the spoon switch does, look at the diagram. SS input on the left is the switch. Everything downstream must therefore be good, your problem,goes back to the PIA.

To check pulses on the diagram, you need to look at the key in the document
SSe: U54 (pin 19) to U49 to U50 to Q76 to Q77 and match the devices to the diagram. If it shows a positive pulse out of Q76, you set your DMM to DC voltage and put the positive probe on that point in the circuit, negative on ground. It should read a logic level low voltage when idle. Put the game in solenoid test, watch the display as the test cycles through the coils. When it tries to fire the lower pop, you should see the meter jump rapidly to logic high, if it doesnt, move upstream to another test point. That's how you diagnose that circuit.

I am also interested in the resolution of this issue. Keep it up!

https://pinside.com/pinball/forum/topic/blue-electrolytic-caps-on-pop-bumpers

Well, those components could play havoc with the response if they are wildly out of spec/shorted...if you can short the switch terminals and it works, it's only going to be those three to deal with: switch, cap and resistor.

What capacitor is used on the switch?

100 ohm 1/2 watt resistor and a 22 mfd 100 volt electroylic capacitor (the positive lead connected to the resistor) in parallel to the switch (a non-polarized version of the cap can also be used)

Just so we keep things straight, because it can be confusing referring to the switches as "top" or "bottom", below is a diagram from Vid's guide to rebuilding pop bumpers. The scoring switch is only activated by motion from the mechanics of the coil. That's all that is reported in the test, because it is the switch that is attached to the switch matrix. The solenoid switch has to working to operate the solenoid. If the scoring switch is broken, or even absent, there is no test reporting and no scoring - but the solenoid still functions and the pop works.

1b0d6219df814343187afc4c2b3ec49e69048923 (resized).jpg

You already said you jumpered the tabs on the solenoid switch and it fires - that already rules out driver, pre-driver and U50, basically everything in the boxed in area below is working. That leaves the switch itself (and its local components) as to why it won't fire from the playfield during a game, and back toward the PIA for the other problem of why it won't fire during test.

01d24edea097e6b08a43a758bd12f1f2f58cadb4 (resized).png

During a game you short the tabs here and does it work? and during test mode try the same test.

fb8b6950d74df096a90208e74d607eae62afe050 (resized).jpg

So when you put the leads on either half of the solenoid SWITCH, did it fire?

It would seem that at some point it fired. Half of the input to the 7402 is flipper enable. That should be low during game mode. Trying to figure out what state the game was in and what was jumpered. Tab to tab on the switch? Tab to ground? ....just difficult by text online to determine these important details.