OK...Update  

Scoop spinner diode previously replaced, right turbo switch diode replaced, drop target A diode replaced, trough 3 diode replaced, credit button diode replaced & wiring checked.  Nil value.  The only diode to go is the left outlane...Have to remove crane assembly so my next question is for some reason my gut tells me there is an issue with flipper board....

The flipper board which the manual states I should have is a 520-5070-00 (Rev A)....My Simpsons has a 520-5033-00.....I will try to google to see if compatible before I remove crane to change diode....