Igt s+ door optos

[Brianpg]

I get power to the door side but not the cabinet side how do I trace this down to get power. Thanks

[Stayouttadabunker]

The cabinet-side of the door optics is a receiver opto.
Wires are red and white connecting to a doubled green w/red stripe wires and a solid red wire.
The solid red wire on that line runs back to the single-row, 20-pin J10 black header on the motherboard.
The red wire is in pin #2 on the J10 header.
The 2nd pin is away from the end of the motherboard.

If your motherboard in your machine is in the back wall of the cabinet, the red wire is on the 2nd pin from the left side of the J10 header.
If your motherboard is on the left wall of an older S+ cabinet, the red wire is on the 2nd pin on the J10 header towards the front door of the cabinet.

The 1st pin on J10 is a ground wire....I believe it is connected to your reciever optic too...like I said earlier, the green grounds are doubled.
The other green wire runs to various components on the right wall of your cabinet.

Anyways, with my multi-meter dial set to 20Vdc, and the reciever optic disconnected, I get a fluctuating power reading bouncing between 8.5 - 8.7 volts.