OK. Went into switch test mode, all switches register fine, even the two slam tilt switches. I disconnected the connector from the board to the cabinett, switched on and off - no Slam tilt message... All voltages ok out from the board... This would clear the boards in the backbox being the suspects I reccon.

I isolated the problem by: First cutting the cables to both slam tilt switches in the cabinett excluding them.

When coin door is open the top white switch interlock pin at the side when pressed is what triggers the Slam tilt stuck message.
The wiring continues to the coin door inteface board... Meassured all diodes when game was on but D10 flows both ways.

I removed the board and meassured D10 again. Now it is suddenly fine..(!?)

1. Bit puzzled... Would a "bad" diode not be able to withstand the game current but still able to resist the lower voltage from a multimeter ? I will change the diode nevertheless but am wondering if I'm on the right track.

2. Parallel to this, there is no G.I, no lamps are on anywhere, not even in the backbox.... Is this a separate problem or has the game "locked" thinkig it has been slam tilted ?

3. Are the coin door intelock switches prone to go bad ?

All fuses are OK.

Any input and suggestions what else to look for highly appreciated.

reg
Matt

#2 3 years ago

CKR

Classe

Pinside apprentice

Göteborg

3y 24,650 98 16

Did you test switch 22 "Coin door closed" in the switch test. Did it work properly in the switch test? Only one pling sound (only switch 22 which was affected)?

Regarding point 3, it happened to us two-three times that we had to change the coin door switch, so it not so unusual that they break.

#3 3 years ago

MKK

Flippermatt

Pinside member

9y 34,850 315 10

Quoted from Classe:
Did you test switch 22 "Coin door closed" in the switch test. Did it work properly in the switch test? Only one pling sound (only switch 22 which was affected)?
Regarding point 3, it happened to us two-three times that we had to change the coin door switch, so it not so unusual that they break.

I tried what you suggested and things are now completley weird.... The interlock coin door switch is now double registrering showing two switches being activated.... First message is slamtilt followed by coin door high voltage which is the correct message for that switch.... Now, this is not the only switch... Lots of other switches when pressed are showing a false switch as no 1 and the right switch as second. Not every switch on the P.F is misbehaving but it seems to be concentrated around the upper battlefield with the double ones and then the interlock switch at the front of the machine.

Is there a dead diode(s) somewhere ? Could any of the opto boards make phantom switch registries if broken ?

Thanks
Matt

#4 3 years ago

CKR

Classe

Pinside apprentice

Göteborg

3y 24,650 98 16

It might be a shorted diode or a short in the wiring, but if there is more than one switch that behaves strange, I would start with a reseat of all the ribbon cables in the backbox. Then isolate that the problem is on the playfield and not on the CPU-board, and after that check the opto-boards.

One way to find out if the problem with the switch matrix is out on the playfield is to do the following:
- Remove back glass. Remove the display and speaker panel and lay outside so that you can see the display, but also access the connectors J206 / J207, J208 / J209, J205 and J212 at the bottom of the CPU board.
- Start the game and enter Test mode -> Switch edges.
- Remove the cables located in J206 / J207, J208 / J209, J205 and J212. (You must start the game before disassembling cables, otherwise you get error message "Check fuses F114 and F115".)
- Attach a cable with crocodile clips to each end of J207 pin 2. Attach a diode with banded side to the crocodile clamp at the other end of the cable. Then short-circuit to pin 2 on connector J209.
Switch 22 shall then be affected in the display. If all wiring to the switches is removed from the CPU PCB, the diode is not needed.
If you get the same strange behavior now when switch 22 is affected, the problem is on the CPU-board.

Another thing to test when you have phantom switches, is to remove the power connector to the opto boards under the playfied (J3 on both the 10 and the 24 switch-opto boards on Shadow). Then re-test switch 22 again. If the problem changed, it's a bad opto board.
Reconnect the boards one at the time to see when the problem changes, to help isolate which of the two boards that is the problem.

Switch testing (resized).png

Post last edited 3 years ago.

1 week later

#5 3 years ago

MKK

Flippermatt

Pinside member

9y 34,850 315 10

An update. Disconnected all the connectors you suggested and tested with alligator clips and diode. All switchtes in row 1 & 2 are double registrering so I guess I have isolated the problem to somewhere on the board.

Is it then chip U18 that has self destructed ?

Would all the out G.I be still connected to this problem or are the dark lamps another case ?

Thanks Matt

#6 3 years ago

LTG

Pinside member

Hopkins, MN

12y 191K 56,936 24 7

OP
Quoted from Flippermatt:
Would all the out G.I be still connected to this problem or are the dark lamps another case ?

G.I. lights have nothing to do with your switch matrix. More likely fuse, bad bulbs, burned connector.

LTG : )

#7 3 years ago

CKR

Classe

Pinside apprentice

Göteborg

3y 24,650 98 16

I'm not sure, but if the slam tilt register as soon as you close the coin door, could it not be the slam tilt that turns the GI off?

Regarding the switch matrix, I would have started with changing the U20, it's socketed on the WPC-S games. The switch matrix behaves strange when that is broken, sometimes it's also rows that behaves strange.
If that doesn't help, then I would have changed U18.

2 years later

#8 1 year ago

DLZ

SadSack

Pinside member

10y 48,900 1,589

A lot of times you can get rid of this problem by reseating the chips on the MPU.. especially the ASIC. I know this thread is old, but this tip can save you hours.

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