This Gottlieb Stargate doesn't seem to have power to the upper left upkicker opto. The #1 Light stays on on the Quad opto board. I've replace both the receiver and transmitter. Checked the wiring and ohms out good. The big resistor on the Quad board had one side broken loose, resoldered it, no change. All components on the board check out good. Even changed the chip that is associated with the circuit, but haven't tried it yet. Any other ideas? Farther upstream?

I'm going to check the resistor board next. Any chance it could be the driver board? Thanks.

Thanks for the response, wayout. All the other switches in the matrix are working correctly. For some reason this opto is not getting power. It doesn't register with my digital camera, and the light on the opto board is on all the time, which means the switch is registering as closed. (The light beam is being broken) In my limited experience with optos, lt's always been the receiver/transmitter. Not getting power is a new one.

Phish, all of those switches behave correctly. There are four optos that run though the quad opto board. On gottliebs, the opto boards have LEDs that will illuminate when each switch associated with the LED is closed. 3 of the 4 LEDs on the board work correctly. The other one illuminates immediately on powerup, indicating the switch is closed. Same thing in switch test. For some reason, the strobe (#8) is not completing the circuit. I was just wondering if anyone had ever had the point of origin for the strobe fail. I think it comes from the driver board, and then returns back to the MPU. I guess it could be a connector problem, but I reflowed all the connectors on the quad board.

Another problem is the machine is 35 miles away at a friends house. Thanks for the suggestions so far.

Well, all work correctly except for the switch in question, switch 80,upkicker.

Yeah, that's what I thought, too. I basically rebuilt it except for a couple of resistors that tested in spec. It's a real simple board. That's why I was wondering if the strobe could be dying at the source. But that can't be right, because other switches in that row or column wouldn't work. Hmmm.

I'll be going back up there in the next day or two to work on it some more and recheck the connectors. I'll let you all know how it goes. Thanks for all the help.

EDIT; Sorry phish, I thought you said quad board. The resistor board is definitely on my radar.

Just to put closure to this thread. I thought I was careful, but both the transmitter and receiver were wired backwards. This tells me, (A) The replacement opto boards from Marco are opposite the originals, or (B) I'm a complete and total idiot. (Going with B) I just ASSumed they were the same. Thanks for the suggestions, everyone.