New! Dark mode!

Browsing Pinside at night? Getting tired of all the white? Switch to dark mode using the button in the top right (or CTRL-B)!

(Topic ID: 91873)

Backbox GI lighting issue for Who Dunnit?


By Willy39

6 years ago



Topic Stats

  • 4 posts
  • 2 Pinsiders participating
  • Latest reply 6 years ago by Willy39
  • No one calls this topic a favorite

You

Linked Games

#1 6 years ago

I am having a very strange issue with the GI not working on the Green - Green/White wires in the backbox. Here is my troubleshooting:

Wires are plugged in like this on j120 on the board:

Pins 11 10 9 8 7 6 5 4 3 2 1
PW GW P G

- I did test connectivity from the plug to the backbox lighting and there is connectivity on the GW and G wires.

- I tested the voltage coming from the board on pins 10 and 6 and I am getting over 7 volts.

- As soon I plug in the connector to the pins I get no voltage on the wire. The connector is new and the lights on the Purple - Purple/White wires work fine.

I am really not sure what is causing this or how to fix it. I have it plugged in exactly as shown in the manual. Should I reverse it? Like in the diagram below:

Pins 11 10 9 8 7 6 5 4 3 2 1
G P GW PW

Does anyone have ANY ideas as I am running out of things to troubleshoot as this seems pretty simple. Thanks for the help.

#2 6 years ago

Whoops in my first diagram.
PW - pin 11
GW - pin 10
P - pin 6
G - pin 5

in second diagram.

PW - pin 1
GW - pin 2
P - pin 6
G - pin 7

#3 6 years ago

From the coil table:
Backbox insert #1 white/grn is turned on by Q16
Backbox insert #2 white/vio is turned on by Q12

Page 3-10 in the manual is a block diagram of the GI circuit operation. You have one working, so you should be able to do comparison measurements between the two to find out where the problem is. I'm thinking the likely cause here is a failed triac driver@Q16, if the 7V (6.3VAC) is making it all the way to the driver board connector.

"When point A is low, points B & C are toggled high, this turns on the triac and the desired string of GI lights"

#4 6 years ago

Thanks for the info. I will check that out.

Promoted items from the Pinside Marketplace
$ 54.99
Cabinet - Shooter Rods
Lighted Pinball Mods
$ 99.00
Playfield - Other
Arcade Upkeep
$ 79.95
Cabinet - Shooter Rods
Super Skill Shot Shop
$ 28.00
Lighting - Other
Rock Custom Pinball
$ 279.95
Lighting - Led
Pin Stadium Pinball Mods

Hey there! Got a moment?

Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside