CFTBL - apparently it has a 3rd flipper ( credit dot )

[Wotto]

Ok - whats going on here then 

I turn CFTBL on today and see a credit dot - which is unusual.
I go into TEST REPORT and I get the message to check the upper left flipper switch         

Turned game off / on and it remained.
NO affect on gameplay.

A few hours later tonight I turn game on and NO credit dot.

This also happened a few weekends back.

 

[goodolddays]

Interesting .
Just had a look at the manual and J905 pin 5 is Upper Left Flipper Opto and J906 pin 5 is upper left flipper EOS (these are part of the Flipper grounded switches)  (page 3-2 in Game wiring and schematics section)
 
I know Creech is a 2 flipper game but the boardset and loom is common to a number of games .. so maybe you have an intermittent short somewhere in the loom causing this error ??? 

[Strangeways]

Opto boards have two optos. Even though both are not used, they can report errors.

If it is intermittent, it could be the optos on the left flipper. Just clean the optos and it might fix the problem. If it was occurring all the time then check the connector or replace the opto. You can cheat by soldering wires across both optos at the connector (solder side of the board).

[pinsanity]

If cleaning doesn't correct it then swap the opto boards with each other - left with right and right with left and see if the problem moves with the board swap (upper right flipper instead of upper left flipper error).

This will tell you whether the fault lies with the opto board itself or further up the line (connector problems, crossed/broken wire).

[casperthefriendly]

Wouldn't the upper flipper optos be used to enter high scores and change the roll over lanes in CFTBL?

Don't have a CFTBL myself, but I know on a mate's WCS94 (2 flippers), the 2nd optos are used to move the lit roll over lanes and for the high score entry.

The WCS94 would only register the 2nd opto if you pounded the button, so that during a game the button wouldn't get pressed hard enough to trigger the 2nd opto and after a few games, the machine would decide that it was broken and chuck a credit dot. You could clear the dot everytime by pounding the button.

Fixed by carefully bending the opto interupter a little so it cleared the 2nd opto.