Dynamo Air Hockey Table not registering points

R3LL1K

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Hey fellas, hope someone here can offer up some advice on how to fix this issue. I'm helping a friend out who owns a Dynamo Air hocke table, the game works just fine except one side isn't registering the points whenever the puck drops on that side. I removed the metal protective plate and cleaned the opto hoping that would correct the problem but it didn't. When the plate is off the opto registers an object passing in front of it but with the cover on, it doesn't work. Any ideas on what the issue might be? I was thinking about replacing the opto board but the opto sensor is registering with the cover off so that can't be the issue can it?
 
Does the metal plate have the black sticker on the back where the opto points? You get flaky results if that's not there. If it is missing you can use flat black spray paint in its place.
(take the other side off and see what it looks like on the back.)
 
Also could be the emitter led is not working so when the cover is off the ambient light serves as the emitter? (could be talking out my @$$ here)
 
There is no sticker, I thought about painting it black but now that I think of it, shouldn't it be silver or some other reflective color? It seemed that it needed ambient light to work and when I popped off the other side the other opto assembly didn't seem to be emitting any light either so I figured it had to be something else. Does the emitter produce infra red light?
 
On mine, it definitely needs to be flat black. The reflections of anything else would not let it work reliably.
Yeah, I assume the light from the LED is not in the visible spectrum.
You can narrow it down easily by swapping the control boards from one side to the other and see if the problem follows.
 
Air Hockey

It has to be flat black. Paint a good part of the metal across from the LED assembly. When you reattach the puck shoot Make sure no extra light is coming in.

Also clean the LEDs. Que Tip and some Iso Alcohol. And it might have gotten out of alignment. The wider painted area will help. One coat should do. Clean and scotch brite the surface ahead of time.

Is this problem for both sides?

Coin up a game. If I remeber corectly you should be able to see the Light from the LED by using the camera on your cell phone and viewing the LED on your phone screen. That will conferm the Emitter Diodes are working.

Radio Schack has the Emitter/ Reciever Diodes

RJ
 
Does the entire table top have to come off in order to gain access to the opto board?
 
Does the entire table top have to come off in order to gain access to the opto board?

No, just remove the goal end cover. This will expose the upper metal curved guide plate. It should have a green ground wire attached to one of it's mounting screws. Just remove both screws and that curved plate lifts up and out. Now there's a nice hole to put your hands in to remove the optic board.

The optic board unplugs and I think there are two screws holding it. Be sure to inspect the optic board for cold solder joints and that the optics are clean and attached securely to the board (no broken leads)
 
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The opto sensor works so does anyone know what type of IR LED might be used in this board? I think that replacing the IR LED should fix the issue.
 
Hey Folks, just wanted to post a follow up to this issue, I guess there was too much light being reflected back to the sensor by the cover. I spray painted the inside of the cover with some flat black paint and it solved the problem game is registering pucks like it should now.
 
i was going to suggest the puck was the problem. I see this all the time with people who replace the puck with either a translucent puck or one slightly smaller than the original...
 
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