Started a game today and when booting up and starting a game, sounds like game wants to do a check ball sequence by firing solenoids. Game started fine and then when start button was pushed, lower right popper and upper right popper started firing one after another for 5-6 times with ball in shooter lane. Game seemed to play fine, but then when you hit ball into either popper, it didnt register and would only do a ball search again to eject.

Went into test mode and all switches test normal, 2 poppers are registered closed and open when a you block optics. Thought it might be a ball trough issue so checked the trough switches and they seemed fine, but did a small adjustment on the one closest to shooter lane as it didnt look like wire was moving down enough to trigger switch signifying ball was there.

Any other thoughts? electrical ? All wires appear in tact, just seems like a mechanical issue.

Still troubleshooting. So I noticed in switch test, you can see lower right popper fire, but when i activate switch #38 ramp up and down it double chimes and the right lower popper switch is activated immediately. Got to have a shorted wire somewhere I think. lower right popper is 37. Switch matrix shows #34 right popper, 37 lower right popper and 38 ramp up and down all in a row. I have always been told to look at the switch matrix but not sure where to go from there. they all use a green orange dedicated ground wire- is that where i start? Trace that ground wire and look for something? or does this suggest a problem on the board? Thanks for help- still learning.

Also I guess I check connector J206 pin 3 for something as well?? After that when you get into transistors I am lost

Switch matrix shows correct switches closed. optos test fine and the problem disappeared but i t will come back

So still working on problem. I have been able to recreate the problem by pressing and opening the up down ramp switch. As soon as I do that the poppers start popping.

Don't see any loose wires. Suggestions on where and how to start?

I have changed nothing and not worked on this machine in 5 years. Play it all the time. First time we have had an issue. So I have read about the switch matrix issues but don't know where to start in narrowing down. How do I isolate and locate the actual issue

Wow othis is gonna be complicated to decipher since the phantom switches are optos

Okay, I removed pinballs from trough and closed coin door so I could see what the switch matrix showed. I have attached a picture to describe.

On startup, switches 37 and 34 fire ( poppers on VUK) and keep firing during intro.

Go into service menu and diagnostics and go to switch edges test T.1 See diagram- switches22( coin door) and 24 ( not used) show closed- marked in blue in pic.
Switch 38 ( ramp up and down) flashes irregularly between closed and open - red in diagram. if you push ramp down to open switch, on release switches 34 ( right popper) and switch 37 ( lower right popper) toggle closed.

In reading and trying to understand switch matrix, the issue could be a diode or bad switch from an area in relation to these, but i am having trouble seeing the rectangle I should be looking at. Also the flickering of switch 34 in the matrix confuses me- perhaps this switch or diode is just bad. But I want to learn and analytically figure it out.

I have a new DMM with a diode test coming tomorrow so I will start to test things better ( my old radio shack one doesnt have a diode test), but can someone help me understand a bit better the rectangle theory and which diodes and switches to check

Thanks

CFTBL Matrix (resized).png

Second test tonight shows only 22 and 24 closed. When I activate switch 38, 37 and 34 light closed, but nothing on the actual switch 38. ???

No batteries on board. Always have them removed. Have been fro 8 years since i refurbed machine

yes will do. Was going to first check mpu and jumper each pin to make sure switch matrix is correct. Then if so, I will need to test the diodes. I still am unsure of the rectangle to check as it talkas about you have to have a closed switch in the same column and the same row, and that gives you the three corners of the triangle and I dont have another closed switch in the column with switch 38.

Yes it happens with playfield pulled out

So O came back from the weekend and no go back to test. Previous;y as I stated on switch matrix switch 38 was flaky, bouncing. between open and closed. this is the ramp up and down which is NC switch. In switch test not registering as closed or open- doesnt respond. However if i manually open and then reclose , upon closure the two poppers 37 and 37 flash closed. removing the optos from the opto board, they beep once each and then when you activate the ramp switch 38 they do not trigger closed.

Should I start with replacing switch #38 which doesnt appear to work now? Perhaps in fiddling with the connectors I damaged something What does removing the opto board signify in the diagnosis.

Thanks

sorry the two poppers are switches 37 and 34

Will.check but they do work in switch test

will check continuity. How do you check if switch is bad with DMM?

So finally decided to start at MPU. Removed connectors 206,208. Jumper pin 1 208 and went down the line. pin 3 ( which is the affected column) nothing from MPU, checked 207 same. So I am assuming the MPU has an issue which would make sense since I havent done anything to the machine. Am I on the right track? And if I am repair MPU or new board. Dont see battery damage and batteries havent been on this board since I have owned it for 10 years

I assume you mean do the swap and then just check the switch test?

got that but I assumed the jumper test with column failure shows its the board?

Okay I tested continuity at pin 3 J206 to U 20. Not sure of pin number on U20-, but the bottom right toned as pin 1, next one as two and I assumed next was three ( no tone) , 4 five six all tested good continuity. Not sure which pull up resistor and 12 volt to check though- I see 12 volt on pins 6 and 7 of J210, but how to know which resistor

Okay so checking continuity from pin 16 of U20 to both R69 and C13. the banded side of resistor no continuity, other side yes. the capacitor continuity on short leg, no continuity on long leg. That should be right as all pins of U20 and their corresponding resistor and capacitors measure same. Measuring resistance- all are right around 1K and not sure how capacitors are measured, but in same resistance mode all are same. So in my learning quest, sounds like the actual internal logic in the chip is bad?

Or wait since their is continuity from U20 to rR69 and C13 and we lose continuity from these to J206 pin 3 is the issue that there ia trace ruptured between R69,C13 and J206 and U20 is fine?

so the flow is from U20 to R69 to C13 to J206 correct? If thats true I have lost it at the C13 to J206 connection. cannot see a trace , header pins are reflowed and good. do not see the connection from C13 to J206. Perhaps the cap is bad? How do I test that?

Ah I see I cannot test unless under load. Now we are getting too tricky for me. Hopefully Chris Hibler to the rescue-lol
But ty I have learned a tone in trouble shooting.

Thats what I thought- its not socketed. Ill get Chris to check it out and he will socket it for future issues. First time I have had an issue with an MPU in my 25 years.

So I am due. Thanks for al your help.