With the game powered off and the dmm set to diode test, red lead on ground and black lead probe all the solenoid driver transistor tabs that are used for the sound board to see if any are shorted to ground.

Logic probe test would be to put the game in rolling solenoid test and watch with the probe on the 4050 buffer on the sound board. Normally they will be pulled high but sink low when the driver board transistor is triggered. Watch each toggle from resting high to briefly low when it's turn comes up in solenoid test. You can follow these signals all the way to the PIA.

Yeah that transistor is probably bad. Remove the connector and see if it clears reading short.

Best to use the diode test for that check, but resistance test showed a dead short. Two clicks on dmm counter clockwise.

Time Warp sound board worked in your Flash. Flip that around, try the Flash sound board in the Time Warp and see how it goes. You want to narrow down the problem.

Did you check the chips and logic gates which drive the transistors? A $15 logic probe helps here.

Also as a general rule, some header pin solder joints are bad on most Williams games of this vintage, and the CPU <> Driver interconnect usually needs replacement.

The big problem is that you grounding the transistors did not fire the sounds.

Like all the transistors are stuck on (seems unlikely), or there is not an actual connection between boards (broken solder joints on connectors).

Pull connector 10J3 off sound board (check my memory,lol) and ground a pin for a millisecond. Does that fire a sound?

Do me a favor.

Pull the sound card out and give be a pic of both sides.

Especially make sure the rear of the male pins of 10J3 are in focus

if you are getting noises when removing plugging in the connector i'd have to think one of the inputs is pulled low otherwise the sound board would not respond.

So you isolated the problem to the mpu/driver and not the sound board right?

You found a shorted solenoid on your driver board up above. Perhaps that solenoid is still locked on because the predriver or whatever is damaged / locked. There are certain input patterns that call for silence... perhaps your shorted input is the one that silences the board????

need a logic probe before i can really tell you to go on. I think you need rolling solenoid test mode and monitor every input signal (with a wire attached on SB) and follow it through the 4050 buffers to the PIA. The inputs should be pulled high and then sink low briefly during its turn in solenoid test. See if one is permanently low.

I was hoping that the 9pin on the sound card had a bunch of broken solder joints, but no luck.

If the card worked in the other game, then you know the problem is probably on the driver board.

You could swap driver boards, or get/make a logic probe.

With the machine powered up, and everything connected, measure the voltage from the solenoid transistor tabs to ground. (Q31, Q33, Q35, Q37, Q39)

If each is near zero volts, something is turning those transistors on (assuming the transistors are good based on the transistor check you performed earlier).

Measure IC3 pins 3, 6, 8, 11 and IC4 pin 8 to ground. Let us know if you get near 0V or near 5V on each of those pins.

use dc volts but the fact you got a different reading on q39 probably means it is turned on. Is that the same transistor you found shorted and replaced up above? Perhaps the circuitry behind that transistor is bad and locking it on.

Pin one is bottom left and counts counter clockwise to top left.

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The long edge of the triangles are the inputs to the 4050 buffers. When the game is in rolling solenoid test the input pins should be sitting high (5.0v) and then sink low for a moment during their turn during solenoid test.

The point of the triangle is the buffer output. Since this is a non inverting buffer with no enables, the output will match the input always

Q39 is stuck turned on or has a collector to emitter short.

IC3 and IC4 on the driver board should be 7408 (pinout posted). Pin 1 is on the end of the chip with the notch.

I agree with Andrew that Q39 is either failed shorted or being turned on by something upstream. You can either shotgun replace the pre-driver and driver or you could check IC4 pin 8 to see if it is high (near 5V). If it is low (near 0V), your pre-driver or driver is shot. If it is high you should measure the voltage of the inputs to that gate, pins 9 and 10.

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Hey Alex, those measurements on IC4 look correct.

I suspect the wiring for Solenoid 13 back to the sound board is not working or you have a problem with your sound board (unlikely since it worked in Flash). Here is why.

There are pull-up resistors on the sound board that pull the voltage up to 5V when the solenoid transistors are off. This makes the reading on the tab of the transistors close to 5V when the transistors are off. You are getting 5V on all but Q39 when all transistors are supposed to be off. The readings you listed from IC4 tell us that the upstream components are not turning Q39 on. So the next logical thing to check is that the wiring for Q39, Solenoid 13, is good back to the pull-up resistor on the sound board.

The signal from Q39 leaves the driver board at pin 3 of J9 (counting up from the bottom) and enter the sound board at J3 pin 7.
As a first check, make sure you have re-flowed the solder on all pins of driver board J9 and sound board J3. Remeasure the voltage on the tab of Q39
Remove the connector on sound board J3, measure the voltage at pin 7 (count from right to left, pin 1 is the key and there will not be a pin). If this is 5V continue. If this is not 5V, you have a bad resistor on your sound board.
Carefully inspect the wiring between the 2 boards, especially the connectors on both ends and especially the pins of interest listed above.

Also, check R67 on the driver board to make sure it hasn't failed open. It should be 2.7K

Those readings are odd. Make sure your meter is set to DC volts. Use a ground point on the board. The ground test point, mounting screw. They should be closer to 5v or 0v. Not in the middle like that.

B side ports on a 6821 only drive to TTL high, I don't think there are any pullups on the pia ports. But still I am surprised the blanking (ic4 pin 9) is that low tho and that the 7408 output is only driving 2.2v. I think the blanking should sit closer to 5v... maybe it getting dragged down somewhere.... blanking can be a a pain because it goes to so many places.

This is where a scope or logic probe is nice... is it 2.2v because P8 is oscillating and that is the avg voltage or is it a flat line 2.2v because of a blown chip.

Guessing the PIA or that 7408 is bad.... i would probably do the 7408 since you had a shorted transistor.

And again very odd a solenoid transistor for the sound board would be bad... hrmmm .... i wonder if a connector mixup happened at some point in the past.