Williams Solved Comet (Williams, 1985) Switch Matrix Confusion

[Philly_pa]

Williams 1985 Comet:
Yes, I have the manuals.

Switch Matrix Row 8, Column 2 & 3 (Aren't functioning)

From what I can tell the Switch & lamp matrix circuits all most work like a common electric series circuit. Meaning if a wire is opened (broken or loses its connection) the remaining elements behind that open will not work or get electrical power. Of course "behind" the element in this case can be either before or after the element depending on where the open is.

Therefore I am confused becaused two elements (#16 & 24) on a common Row (#8) within the switch matrix aren't working (registering during game play) yet the remaining elements on the row behind them work properly (elements 32,40,48). I have validated conductivity on all element connections on that particular row. As well as confirmed conductivity of the wires on the column side of all the elements in question.

As an additional test step, I removed the two suspected non-working elements (a stand-up target & a hole eject switch). Created a simple circuit with a 9v battery & 1 PF lamp and placed the suspected element in-between the battery & lamp. The suspected non-working elements & its attached diode worked fine as i was able to light the lamp when the correct polarity was applied.

This leaves 1 element (#8) the (High score reset switch) on the row that could possibly be the problem. I have NOT placed it into the 9v to 1 PF lamp circuit test, however I did do a conducttivity test thru the switch with the Multimeter (up= no conductivity, press down = conductivity).

What did I miss? What did I forget to check?

And YES, I am aware that element #24 (Eject hole) switch will only sense/acknowledge when a ball is in the hole. Solenoid #3 will fire & eject the ball out of the hole. This solenoid does fire upon "power-on" test as well as when the machine is in the solenoid test mode.

 

[pinballdaveh]

did you do your wire resistance tests starting at cpu connector 1P10 @ 1J10 pin 1 white/grey wire to each white/grey switches on row 8 including high score reset button

 

[Philly_pa]

Re-soldered several small jumper wires leading up to the non-working components/elements. Went to restart machine to re-test after re-solder effort but somehow I blew a fuse on the game. I am currently out of stock on fuses.
Yes, I have performed a continuity test from the CPU board all the way to ALL the elements on the row in question.

 

[Philly_pa]

Resolved fuse issue.

However my re-solder efforts did not cause the non-working components/elements to start working.

I have also noticed the switches are not wired in sequence as described in the manual's switch matrix grid.

For some reason row# 8 is actually wired From back box to Rabbit # 3 (not working) to Right Kicker to left Drain special (not working) to Top-jet bumper, to Fun House eject hole (not working) & then back to the Back Box (where I believe its reouted to the High score reset switch (not sure it works either) on the coin door.

I am confused because the manual states the White/Grey wire should go from Back box to High score reset switch to Rabbit # 3 to Funhouse Eject to Left drain special to Upper jet bumper and then to Right Kicker.

So now I will try to place a jumper wires from the cpu board directly to the non-working component/element ( that would be both Row & Column wires)& see if that makes a difference.

Again, when I removed & placed these non-working elements into a circuit with a 9volt battery and play-field lamp, they work properly.

 

[Philly_pa]

RESOLVED!!!!

Wow, that was a wierd issue.

It seems the Grey/White wire at the CPU connector (PinballDaveH told me to check it!) was actually broken on 1 side. The wire is supposed to make contact with the cpu board via two wire piercings on the connector. Well one side was working and the other side was totally disconnected.

The wierd thing is several of the elements on this wire/row worked & some didn't. None-the-less after fixing the open at the connector, all the components are all functional. YEAH!!!!!!

Thanks to all for your help and assistance on this one. And a VERY BIG thanks to big brother PinballDaveH, you're the MAN !!!

 

[Coil_Smoke]

I Second That Emotion

RESOLVED!!!!

Wow, that was a wierd issue.

It seems the Grey/White wire at the CPU connector (PinballDaveH told me to check it!) was actually broken on 1 side. The wire is supposed to make contact with the cpu board via two wire piercings on the connector. Well one side was working and the other side was totally disconnected.

The wierd thing is several of the elements on this wire/row worked & some didn't. None-the-less after fixing the open at the connector, all the components are all functional. YEAH!!!!!!

Thanks to all for your help and assistance on this one. And a VERY BIG thanks to big brother PinballDaveH, you're the MAN !!!

Glad you are on your way to pinball nirvana... And how about the amazing posts that come from PINBALL DAVE H .