Hey guys,

I hope someone has seen this weird issue on Twilight Zone!
After we start a game, the machine, by itself, adds additional players to the game. So it is almost impossible to play single. Most of the time this happens.
We thought the issue was the start button switch and replaced it.
Nope. The problem is still there.
Cleaned the connector that connects the button wires to the small board on the left hand side of the cabinet.
Same thing.
This issue is driving me NUTS as it was NOT there when I got the machine and started to happen a couple days ago.
Any ideas???

Thanks!

have you tried unplugging the start switch as well?

You mean start a game and then unplug the switch to see what the machine does? Like if something else 'triggers' the machine (and it ends up thinking I pressed it?)?

Thanks!

Get the manual out and check where that START switch is actually going on the cpu.
I'll bet that your problem is with the dedicated switches on the cpu board.


review http://marvin3m.com/wpc/index2.htm#switch for more help

Ok I did some extra testing here. Not sure if what I found is terrible or not.
Keep in mind this is my FIRST Pinball ever!
I pressed start, DISCONNECTED the start button switch and started playing. Once I sent the ball on the LEFT spiral, a second player kicked in and after that (not sure where I hit/sent the ball, a third one showed up). So there is definetly something trigerring the freaking machine and starting a new player.
I have NO CLUE whatsoever where to look for the solution for this. I do NOT have the manual yet (the seller shipped last week) and as I said, no clues.  
I guess I will need some sort of remote assistance here.  

Where are you located? I have a spare manual.

ok had something similar on the flintstones i had trigger one switch and the all go. go into test mode switch edges and triger a switch at a time could be you have a blown chip on the mpu board. look at the link mr hide gave you is the best. for a great repair guy mindstorm88 does fantastic work.

let us know your findings

I had this exact problem on an Indiana Jones, It was all related to a shorted diode on the mini playfield, The bottom right that always gets hammered into oblivion.

I would look at the switch matrix and check every switch on the Coloumn and the Row for a broken or shorted diode.

Dave

I found which switch is causing the issue. On the LEFT RAMP there is a switch (when the ball enters the ramp). That one is trigerring multiple things when I trigger it, including the start button!
So my next step is where I look for this? Where is the switch matrix? Yep, I am a newbie at this.
But as an Electronic Engineer I will learn and learn fast.
I am located in Ottawa in case someone has a spare manual. hehehe

OK, Check the Diode on that switch, I am going to assume you are really new, so don't take it personally if not. The diode is the Barrel shped component across the switch. Make sure that the leads aren't off on either end and that they are solid in the middle, as in not loose where they go into the diode. You can test the diode, but you need to remove 1 end and be able to solder it back on. The switch matrix is a chart that shows which switches are "Daisy chained" together. This means that the switch in question might not really be the problem, It might be up stream. This chart is usually stapled inside the back box or in the cabinet somewhere. You can download a manual at

http://www.ipdb.org/search.pl?any=twilight+zone&search=Search+Database&searchtype=quick

scroll down to documentation a bit above all the pictures.

http://marvin3m.com/wpc/index.htm

Also, Go read this link above.

Dave

By the way, Is it possible that this was doing it before and you didn't notice it? Silly I know, but still... Make sure the diodes are properly oriented. The banded end should go to the side of the switch with no wire. Green wires in the middle other wire on the other end. The banded end of the diode goes to the lug on the switch that is farthest away from the middle.

When I got my Tales From The Crypt there was a diode on backwards and when you made the right ramp, it thought the ball had ended! That was a tough one to find!!

Dave

Not that I am aware of. It was just fine and then started acting like that.
I could see exactly what you meant. All the diodes under the rubber caps. They all seem good and with good soldering. Nothing I can see is wrong.
The odd thing is the left ramp one for example was triggering the start button. On the game and on the switch tests. I tested many things on the machine, ran a burn in and tried again. Now it does NOT trigger the start button anymore. The ramp exit one was triggering the tilt plumb. Not anymore. So the main weird thing is this issue is intermittent; sometimes happens and then disappears! The left ramp entrance now does not mess with the start button BUT it mess with other things like the LEFT MAGNET. What may be the deal here?
And when we fix this kind of issue, what this usually mean? Replacing diodes? Or something deeper on the boards for example?

Thanks! I learned a lot in one night.