Opto switch alternatives/mods?

[tim.sanderson]

I have an incredibly flaky opto on my R911. It seems after every handful of games (maybe ten at most) I have to lift the playfield to adjust the sensor that triggers the top kicker. It's not a loose screw or anything, but I still have to readjust it every once in a while.

Has anybody ever modded a machine to swap an opto for a more traditional-type switch? I'm sure I'll get the opto-thing figured out, but I do like the simplicity of a normal switch!

 

[hippochrome]

I think Geoff(Pinhead) did that on Jon's(jonnyeh) old TZ...it did the trick on his flaky flippers

 

[Menace]

I would highly suggest you do NOT convert from opto to mechanical switch. The amount of time and effort you'll go through to accomplish this Tim, it will be WAY easier to replace the opto's in your game with new ones. There is no reason you should be having to adjust these, so something isn't right. I say buy a new opto emitter and receiver (part#'s in your manual) and replace what's in the game and go from there.

D

 

[thewebexpert]

To chime in, they are like 30 cents a piece online as well .... At least the ones for Dr. Who are ...

 

[tim.sanderson]

I think I may have gotten the switch to behave a little better, I've added a washer to the shim that lines up the sensors board with the LED. For now the switch seems OK.

It's definitely not a cost thing. I'm just worried that if I replace the opto switch, it'll still be flaky.

 

[Menace]

Opto's generally are more robust than micro's, and were used in places where using micros' are difficult or impossible to use. Once you get it set right, you shouldn't have issues with it.

D

 

[REVOLUTION]

also have you cleaned the opto LED's? They could just be dirty.. remember it needs to send / receive an invisible beam of light.

worst case, just buy a new transmitter and receiver LED and solder them in. $1 and you're done.

Ask any STTNG owner, they'll tell you how much fun Optos can be.. :FP:

 

[WARLOCK]

Ask any STTNG owner, they'll tell you how much fun Optos can be.. :FP:[/quote]

Woo hoo! NOT! PITA optos. Regular cleaning is key.

 

[tim.sanderson]

I've heard about the STNG opto thing, sounds like it has it much worse that R911!
Yeah I've cleaned them. Even when they are screwed down tight they seem to wiggle their way out of place.

 

[bstock]

I'm still a noob, but I would also think that first replacing the transmitter and receiver optos would be a cheap easy thing to try. If it doesn't work go from there, but from what I've been told these switches are quite reliable.

 

[good_buddy83]

I've had the LED break a wire between the LED and the solder pad, which you will never ever see. I had to wiggle the LED to discover it was completely disconeected. I imagine this happens over time with the vibrations of the machine. This leads to intermittent operation. I have 2 of the exact circumstance on my Shadow. I soldered in new LED's and everything works well now. I would reccomend replacing the whole emmitter/receiver boards as well if you can, as this is a small board to work on. Also a good IR detector helps. Don't use new I-phones as they filter out Infared really well. I have an old 3G I phone I keep in my pinball repair box for this reason. Open the camera app and look at the infared through the phone. The emitter should show up bright pink if it is wroking. Knowing if it is an emitter or receiver issue will help to eliminate at least 1/2 your problems.

 

[tim.sanderson]

IOpen the camera app and look at the infared through the phone. The emitter should show up bright pink if it is wroking. Knowing if it is an emitter or receiver issue will help to eliminate at least 1/2 your problems.

That's a fantastic tip! It works like a charm on my HTC.

How susceptible to alignment are the transmitters/receivers? I've changed the spacer that holds the transmitter, and now it always seems to think there is a ball between the sensors. (I changed the receiver spacer to the same one I changed the transmitter to a week ago, and it seemed to work fine)

 

[tim.sanderson]

Hmm scratch that, the transmitter doesn't seem to be working any more. I'll have to pull that board out again.

 

[tim.sanderson]

No wait, double scratch that. It looks like it actually does. :FP:

 

[good_buddy83]

Sounds like intermittent operation to me. I would replace both emitter and receiver to be sure. I had the same issue. It would work for 2 weeks, then stop for no reason.

 

[tim.sanderson]

Sorry I meant that the transmitter still works. (I can see it glowing with the phone trick) It still thinks there is a ball in between them. I think it's an alignment problem. I have a few hours before work to try and get it sorted out.

 

[Menace]

Just remember that opto's work the OPPOSITE was regular switches do. If the game thinks it's ALWAYS seeing a ball, and the emitter is working all the time, then it's an alignment issue or the receiver is borked. Usually there isn't much to aligning these things because the distance between them is so small, and the factory hole locations should force them to be lined up automatically, so I would for sure replace the receiver.

D

 

[tim.sanderson]

OK, so if I am correct;
The emitter is the LED that I can see glowing when I look at it through my phone. (the LED itself has a little bit of colour to it when viewed by the naked eye)
The receiver is a clear LED. The one will not show up when viewed through the camera.

Is the emitter supposed to be on all the time? What I've been thinking is that the switch works by having the beam broken by the ball. As long as the receiver thinks there is no ball in between the sensors, it shouldn't trigger the kicker. Or am I wrong?

 

[Menace]

You are correct on all counts. The emitter is ALWAYS on no matter what. The receiver sees the emitter which tells the game there is NO ball present. When the beam is broken, ball present. If the receiver is borked, it will think there there is a ball present all the time and the game should be trying to kick the ball out. Now there could be software in the game the compensates for this and eventually will "ignore" this switch in which case when a ball enters this area the only way it comes out is during ball search. Usually what would happen is when the game is powered on it will try to clear what it thinks is a ball "X" number of times and then eventually give up, at which point it will "ignore" this switch until the power is cycled.

If it's intermittent and the emitter is in fact always working (if it ever goes out, even for a second due to a cold colder or whatever the game will think it's a ball breaking the beam) then it's a bad receiver or a bad connection from the receiver back to the switch matrix somewhere.


D

 

[tim.sanderson]

I think the rec. LED is bad. When I test the emitter with DIODE mode, I get a reading. When I test this one, it doesn't give me any reading at all.
Is this an LED I can buy anywhere, or is it a specific part?

(also, is that even the right way to test an LED?)