Indy Jones slam tilt when modes finished

[rschieve]

I've been fighting a nasty problem with a WMS Indy Jones that's really got me stumped. The game will slam tilt shortly after completing all of the adventures and no other time. It plays perfectly through all the modes but as soon as you complete them all within just a few shots the game will slam tilt. I've done a 100% switch test. I've swapped out the MPU, the Power/Driver, the flipper optos, and the 10 opto controller under the playfield. The trough switches check out OK. I've use my oscilloscope to look at the switch rows and don't see anything unusual. I've pounded on the playfield with the game in Switch Edges to see if anything false trips. I've started a game and then disconnected the coin door so the slam tilt is not even connected and the same problem occurs.

I've truly run out of ideas to try. Any suggestions would be greatly appreciated. Thanks!

 

[Kilgore]

You have a bad diode on your switch matrix.

 

[Kilgore]

Switch 21 is slam tilt, 22 is coin door closed, so you might not get the same results with it open. The diodes on the mini playfield can get hit by the ball from underneath and that can make them short.

 

[rschieve]

You have a bad diode on your switch matrix.

You are probably right but I get no indication of any problem in switch edges. All the diodes seem to be OK and the matrix looks OK with an oscilloscope when activating switches. And why only the slam/tilt when all the modes are completed?

 

[rschieve]

Switch 21 is slam tilt, 22 is coin door closed, so you might not get the same results with it open. The diodes on the mini playfield can get hit by the ball from underneath and that can make them short.

Something to try with the coin door switch. The dammed machine is 2 hours away so I can't run over and try it easily... I have seen diodes on the bottom of the mini playfield get messed up but you usually get some kind of indication with a 100% switch test in switch edges. I appreciate the suggestions.

 

[Kilgore]

Most switches in the matrix are momentary, but ball trough, drop targets, ball locks and the coin door switch are off or on. When you have a shorted diode in the matrix the switches that are on can help you find the short. For example, on Indiana Jones if you had a ball in the front captive ball lock Sw#71 and a shorted diode on mini top right Sw#75 and you activated the (i)ndy lane Sw#25 it would loop around and give you a false slam tilt Sw#21 reading or if you knew that the last switch you hit before it tilted was exit idol Sw#32 then your bad diode is on Sw#31 becouse your coin door is closed. I carry a few hundred 1n4004's with me all the time just in case I can't figure it out. I just start cutting them off and replace them with new ones. Sometimes a bad diode tests out good so don't bother testing the old ones I do test the new ones before putting them on.

 

[mecha]

from my experiences with pinball, your culprit will be whatever shares the COLUMN with the suspect switch. make sure your switches are all plugged in correctly, I had a Black Knight 2000 where the motor down limit switch had the wires plugged into the NO and NC rather than NO and COM and it affected everything else in the column.

if you have a broken wire on any of the switches, I think that would affect other switches in the column as well.

you can dabble with replacing diodes on the other switches in the column too just to make sure they're all secure at that point if you'd like.

the columns are the important part though. the rows are just a byproduct of the columns.

also, run the SWITCH LEVELS test, see if any of them are sticking on when they're not physically active.

EDIT: something I just remembered, column wiring, if the shared wire color among the switches is broke off one of them it'll mess up the communication as the column talks to all the switches that way. I doubt that's your problem here anyway though considering the game for the most part works except in a certain instance.

 

[rschieve]

I understand your reasoning and can certainly swap out some diodes. It must be a clue that this only happens when all the modes are completed...

Most switches in the matrix are momentary, but ball trough, drop targets, ball locks and the coin door switch are off or on. When you have a shorted diode in the matrix the switches that are on can help you find the short. For example, on Indiana Jones if you had a ball in the front captive ball lock Sw#71 and a shorted diode on mini top right Sw#75 and you activated the (i)ndy lane Sw#25 it would loop around and give you a false slam tilt Sw#21 reading or if you knew that the last switch you hit before it tilted was exit idol Sw#32 then your bad diode is on Sw#31 becouse your coin door is closed. I carry a few hundred 1n4004's with me all the time just in case I can't figure it out. I just start cutting them off and replace them with new ones. Sometimes a bad diode tests out good so don't bother testing the old ones I do test the new ones before putting them on.

 

[ArcadeTechGW]

It may be. Where is the ball when this happens? Start a game, and tap around that area to see if you can get it to repeat. It could be:
- cold solder joint on a filter cap on a switch
- bad diode on a switch
- Loose wire
- Dozens of other hard to find things.

 

[Kilgore]

It's been a long time since I played an Indy I don't know what's going on at that point if the game but if you can get everything exactly the same in switch test, including having the door closed, you might see it, its a square or rectangle just the corners switches show up its not like a ground short. I've been working on pinball for more than 8 hours a day, most everyday for over 36 years and I know that is the problem.

 

[Kilgore]

Any progress on your Indiana Jones?