Creature switch errors .. but why ?

[goodolddays]

Gday all .

My Creech is reporting 3 switch errors , switch 41 (Cola) , 51 (left outlane) and 61 (Right ramp exit) .

Problem is I can't figure out why .

Switch 21 (Slam Tilt) is the other switch on this same row (Row 1) and it works fine which to mu thinking rules out a CPU connector problem or associated chip .

I pulled J209 connector and checked for continuity between pin 1 and switch 61 (the last switch on the column) and it is OK .
Diodes on all 3 switches test ok (tested while connected to each switch though) .

These 3 switches don't register during a game or in switch edges , or single switch test .


This happened at next power up after my daughter managed to sink both balls from the same flipper at the same time into the snack bar hole and they got jammed in there , but can't think how that would be related .

I have also physically checked each switch with my MM and they all test OK (ie open/close) and each diode tests OK.


Appreciate if anyone has any suggestions on where to look for this fault .

Cheers
Dave

 

[Freiherr]

Could column 1 be shorted to ground somewhere? Your CPU board sounds OK so disconnect the connectors from the Coin Door. Also, disconnect the Opto Boards and see if problem disappears. Worth a try.

[goodolddays]

Could column 1 be shorted to ground somewhere? Your CPU board sounds OK so disconnect the connectors from the Coin Door. Also, disconnect the Opto Boards and see if problem disappears. Worth a try.

If it was a short to ground then I would expect to see the CPU to see switches always closed, but it sees them always open   

[goodolddays]

Gday all .

Update

 Switches register closed if I connect relevant pins on row and column connectors on the CPU board so that isolates the fault to somewhere on the playfield .

 Switch 21 (slam switch on coin door) works fine so I'd expect no issue with the coin door interface board or connectors there . According to the schematic , switch 21 effectively terminates on the coin door interface board and is connected back to the CPU via J212 .

 Will have to have another look at these 3 switches on the playfield itself . I guess next steps will be reflow connections on each switch and replace diode on each switch .. will let you know the result .. possible its a connector in the wiring loom somewhere too I spose

 Cheers
 Dave

[Strangeways]

Check continuity of the row/column wire (Green) of each of these switches. Sounds like a break in the return wire. The Slam Tilt has its own return wire but those three switches are daisy chained.

[goodolddays]

Check continuity of the row/column wire (Green) of each of these switches. Sounds like a break in the return wire. The Slam Tilt has its own return wire but those three switches are daisy chained.

Gday Nino .

These switches are all on row 1 . (white/brown wire) 1st thing I thought was a break somewhere on this wire, but have continuity between the last switch (61) and pin 1 on the connector that plugs into the CPU

[goodolddays]

I had another look at this and still can't find the fault .
Replaced the diode on each switch as I have plenty of them , but made no difference .

I am at a loss as to what is causing this problem

[goodolddays]

Still trying to find the time to get back to this .
I did check the diodes are all the correct wway around last weekend when I was installing the Snack bar mod .
Also noticed that switch 41 error has disappeared but the other 2 switch errors are still there .
Also have a new (probably unrelated ) intermittent issue of 'pinball missing' when trying to start a game when all 3 balls are in the trough .

Next step will be to isolate each switch and test

[goodolddays]

Gday all .. still looking for suggestions on this issue ..
Switch 51 and 61 not registering closed .. switch 41 has mysteriously come good (oh oh)

Also have a new more annoying fault which has made the machine unplayable !!

Right trough switch is registering open when another switch on the same column is closed (eg the other 2 trough switches or the outhole switch etc) .. this fault means you can't start a game because the CPU thinks a ball is missing . When all other switches are open in the same column this switch registers as closed (when there is a ball in that trough position), but as soon as another switch is closed in that column then this switch continuously alternates between open and closed (this is in single switch test)

I have replaced the switch because I had a spare and the original (Normally open contact) was not measuring consistently when operated.

I have also checked continutity is OK on both the row and column wires between this switch and the first switch in the row and column.

I have started to read up on fault finding WPC switch matrix issues but any help appreciated .
 

[Strangeways]

Gday all .. still looking for suggestions on this issue ..
Switch 51 and 61 not registering closed .. switch 41 has mysteriously come good (oh oh)

Also have a new more annoying fault which has made the machine unplayable !!

Right trough switch is registering open when another switch on the same column is closed (eg the other 2 trough switches or the outhole switch etc) .. this fault means you can't start a game because the CPU thinks a ball is missing . When all other switches are open in the same column this switch registers as closed (when there is a ball in that trough position), but as soon as another switch is closed in that column then this switch continuously alternates between open and closed (this is in single switch test)

I have replaced the switch because I had a spare and the original (Normally open contact) was not measuring consistently when operated.

I have also checked continutity is OK on both the row and column wires between this switch and the first switch in the row and column.

I have started to read up on fault finding WPC switch matrix issues but any help appreciated .
 

sounds to me like one of two things;

One of the switches is somehow shorted to ground intermittently. Either something silly like a lamp socket or similar is touching a lug of a switch in that row.

A switch is wired incorrectly. Also check the trough switches as there's a common between the switches that can be hanging on by a thread. Check the diodes on these switches as vibration can make them cold solder joints.

[goodolddays]

Thanks for the suggestions Nino .
After some more reading and thinking about it I am also leaning towards a short somewhere .

All these switch issues started after my daughter managed to sink both balls into the Snack Bar hole at the same time (neat trick) and they jammed there ..

Sadly I probably won't get a chance to look at it again now until Monday arvo .. on the upside going to Expo all day tomoz 

[goodolddays]

Well, you were on the money Nino .

I eliminated the CPU board by testing all row/column combinations using the jumper wire method .

On closer inspection the common wire on one of the trough switches was hanging by a thread .. fixed that but still have the trough switch fault .
Have found some cold solder joints on the  NC connection on a number of switches on the green/black column which has improved the trough switch issue but not fixed it as yet . Also reflowing the NC connections on all the blue/white row , but need to get to switch 36 (left ramp enter) as yet.

Reflowed the NC connections on switch 51 and that has fixed the switch 51 and 61 errors 

As usual I was over thinking the problem .. seems like its all due to cold solder joints .

What i noticed is when measuring the NC switch connection the resistance was greater than 1 ohm .. around 1.4 - 1.5 which is high enough to be causing problems .

 

[Strangeways]

Great to hear it is all fixed. 

Sometimes it just needs a second set of "eyes" 

[goodolddays]

Great to hear it is all fixed. 

Sometimes it just needs a second set of "eyes" 

Yep .. not all fixed yet though , have improved the trough switch issue but not resolved it yet

[goodolddays]

Update:-

Replaced U20 (thanks to Gemini2544 for the chip) but unfortunately the fault persists.

To recap : CPU is reading Right trough switch intermittently closed when balls are in the trough . This is preventing game play.
All other switches in the row (and associated column) work correctly.

I rechecked the resistance of the row/column wire between the trough switch and the first switch in the row and found it a bit high (more than 1 ohm) compared to the other trough switches , so bypassed that wire by soldering a wire between the NO of the right trough switch and NO of the left trough switch (they are in the same row)
I previously replaced the switch and the diode (yes , new one is right way around) .

The switch tests fine with a multimeter .

What else can I check .. any ideas anyone as I have run out of ideas.