(Topic ID: 308692)

Stargate opto not registering.

By Bodean

1 year ago

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  • 11 posts
  • 4 Pinsiders participating
  • Latest reply 1 year ago by pins4u
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    #1 1 year ago

    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.

    #2 1 year ago

    Keep in mind an optical switch is just a substitute for a mechanical switch, so you should always check that the make/break action of the switch matrix is functioning manually. Then you can rule out the transmitter if it is a visible light transmitter with just your eyes, or an infrared with an IR detector card. Then last, the receiving opto.

    #3 1 year ago

    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.

    #4 1 year ago

    Ok. I'm not familiar with Stargate and cannot find a manual online, but the theory is the same. Trace and continuity check the power line from the source to the opto. If there is more than opto, and they work correct, this narrows the search. Ground continuity could be a possibility. Otherwise, it could be a source fail for all optos. (For example, if all opto transmitters run on a 12VDC source, that could fail, causing all optos to not work)

    #5 1 year ago

    Does the switch register as closed in switch test? Do the other switches on that opto board work properly in switch test?

    Top left upkicker sw80
    Lower left ramp sw90
    Top left ramp swa0
    Top right ramp swb0

    #6 1 year ago

    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.

    #7 1 year ago

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

    #8 1 year ago

    Resistor board (A13) is definitely a suspect.

    IMG_20220124_175208_3 (resized).jpg
    #9 1 year ago

    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.

    #10 1 year ago

    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.

    #11 1 year ago

    Well done sorting it out and yes, you can NEVER assume that any replacement parts will be IDENTICAL - let's all just be thankful that the important stuff we all need to keep our machines going is mostly available!


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