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(Topic ID: 167366)

Opto volt readings, odd


By ibjames

4 years ago



Topic Stats

  • 36 posts
  • 6 Pinsiders participating
  • Latest reply 4 years ago by ibjames
  • Topic is favorited by 2 Pinsiders

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#1 4 years ago

Now, I'm not really good at this.. if you search my threads you'll see I have a STTNG and stumble horribly.

I have my multimeter set at 20DCV, when I read the voltage on a working opto, it reads 1.3

I have an opto on the VUK that feeds my right canon that reads 9.8.

The odd thing is the old opto worked, I unscrewed it and did the phone test and I could see it was on. To verify this I swapped the opto with my #2 opto on the trough and the #2 receiver registered a break in the field. Feeling crafty, I thought that I figured it out. Ordered the receiver for the #1 spot. Put it in. Still doesn't work. Put in a new transmitter, now that doesn't work either. Then I decided to check the volts. Now I'm lost.

I have the game right now the setting of right canon not working and I can play with 5 balls. If I put the 6th ball in there it will send 2 balls up from the trough every time you go to shoot the ball in to play.

Any suggestions?

I just recently swapped out my cpu board for a rottendog, and just put in a great lakes trough board that all the LEDs are registering the ball and all the tests work.

#2 4 years ago

visually check the opto board under the PF. This is what the one in drac looked like. electro caps where spilling their guts.

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#3 4 years ago

Are you aware that opto TX & RX diodes have polarity and must be inserted in the PCB (or wired) the correct way around or they won't work?

#4 4 years ago

Is this it?

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#5 4 years ago

I swapped the receiver on #1 and #2, and when it is on #2 it registers, so #1 isn't getting to the board to register or something on the board is blown.. sigh

#6 4 years ago

any other games have the same board? I have a few friends with pinball games that don't mind swapping to test if they have the right card

#7 4 years ago

This is what I did today, resolder a kicker wire that broke, swapped a resistor on a stand up target, now I don't have power to any of my boards under the game, the trough, the main opto board, I can't find a blown fuse...
The target acted the same after I swapped the resistor,as I went into the switch test to test it...

I had my door open and I'm switch test as I watched the balls drop into the trough and was verifying it worked the power cut off to the boards.. I thought.. easy.. a fuse.. I can't find anything...

You can't tell from the photo of the target but the wires aren't touching

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#8 4 years ago

Start simple and inspect the board. Look close at the connector pin solder joints. Those boards get shook around under the PF and it can crack the header pin solder joints.

Use test mode and the schematic drawings to figure out where specifically to look at. ie follow the wire colors back to the pcb etc.

#9 4 years ago
Quoted from ibjames:

I have an opto on the VUK that feeds my right canon that reads 9.8.

Is this measured from the two wire solder points on the opto board?

#10 4 years ago
Quoted from ibjames:

I had my door open and I'm switch test as I watched the balls drop into the trough and was verifying it worked the power cut off to the boards.. I thought.. easy.. a fuse.. I can't find anything...

Check your 12V on the power driver board, F115 and F116.

#11 4 years ago
Quoted from Pin_Guy:

Is this measured from the two wire solder points on the opto board?

At the solder points on the board with the little black receivers on it

Are the black things the photos? I'm trying to get my terminology down

#12 4 years ago
Quoted from ibjames:

At the solder points on the board with the little black receivers on it
Are the black things the photos? I'm trying to get my terminology down

The small, round black plastic packages with (usually) two legs are "opto receivers". The one at the the other end of the (invisible) light beam is the "opto transmitter" and (usually) they are in a clear package but can be a light pink.

In most pinball applications, they both are wired to a control circuit that is usually close by and the signals are handled by that board and passed on to the main control board (the MPU).

Both are diodes and MUST be connected the correct way around - IE: they have polarity.

#13 4 years ago

Optical Transmitter is the green circuit board with the A (anode +) and K (cathode -) markings on it.

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#14 4 years ago

Optical receiver, this is a phototransistor and is usually a blue circuit board to avoid confusing it with an emitter board, although some after market ones are green.

A photo transistor is basically a light activated switch, when light hits the transistor it turns on...when its on, the voltage applied to the collector of the transistor (C) conducts through it , so what you measure is the internal loss of the transistor (~0.18V), that's how we can tell its on.

Now if you block the the IR beam, the transistor will turn off and you will measure the source voltage on the cathode (C) and since the Emitter (E) side has a path to ground you will measure the source voltage (~12V) between the Emitter (E) and Collector (C).

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#15 4 years ago

The technical stuff...

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#16 4 years ago

Yes; that's your 16 OPTO board, and it looks pristine, I wish mine looked that good. There are only a couple of games that used that board: Star Trek, Dirty Harry,and Who Dunnit,

#17 4 years ago

how do I measure the power on those?

On 115 I had nothing
116 I tried to measure but it reset the game so I got nervous, I'm not 100% sure how to measure on that, I don't want to break it more. I think there are 3 posts punched down, with the 1st and 3rd posts being grey and the middle being black, I should be putting one on the middle post and another measuring tip on the grey right?

118 has some leds on it, and they do not light

#18 4 years ago

These are measured with the black meter lead on ground, and the red lead on what you are measuring. If you have clip on leads, you can just clip it to the ground braid or something metal like the light board locking bracket. it seems like you have a lot of unrelated things going on, so to prioritize them lets just work solely on getting all your voltages working first.

If you had nothing on F115 (fuse 115) with the above check, then unseat the fuse and check the resistance of it with your meter, it should be close to zero. If the fuse is good, then you probably have a blown bridge rectifier, this happens and it's an easy fix but they usually short and blows a fuse when they failed; this is something you want repaired correctly, PM me if the fuse is good and you have no voltage.

Quoted from ibjames:

118 has some leds on it, and they do not light

I'm sorry I don't know if you are referring to, please post a pic of this point on the board, and I'll happy to provide more information.

#19 4 years ago

Ugh, sttng is a nightmare of a game and Im starting to wonder why anyone would own it.

#20 4 years ago

I PM'd Pin_guy

I checked the f115 fuse location and it gave me a 12V readout. I swapped the fuse and that didn't help things either. I'll update this later with any new findings

#21 4 years ago
Quoted from Djshakes:

Ugh, sttng is a nightmare of a game and Im starting to wonder why anyone would own it.

Mine has no problems and plays great!

#22 4 years ago

Reply sent

#23 4 years ago

When I referred to the three prongs in my PM

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#24 4 years ago

More pics

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#25 4 years ago

Just in case you need it pictures

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#26 4 years ago

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#27 4 years ago

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This isn't factory and is connected to your 12V, remove it to see if your problem persists.

--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com

#28 4 years ago

All right, so after making some checks it seems we are good at the transformer and verifying that the source voltage is probably good at that point, but reading no AC voltage at J112 and an open circuit on a continuity check. I'm starting to question the validity of the check that was previously made at J112.

This can be a difficult check to make by yourself if all you have is a basic meter; one of the easiest ways to take this measurement is by checking on the backside of the connector where you have good access to the pins.
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The circuit resistance should be lower than it shows but I was having a hard time holding everything with one hand and taking the picture with the other.

If you have a couple test clips and and extra socket with 3 or more pins lying around, you can check it hands free and get much better readings. Its hard to see, but I'm checking on pins 3 and 5 of the connector, this is where the transformer wires first enter the connector, and the meter is showing 0.8 ohms resistance.

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Final check ... Turning on the machine to measure my source voltage from the transformer.

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So where do we go from here ...?

Well if you find out you really do have a good connection to the transformer on J112, then you probably have a blown bridge rectifier on your power driver board. If you recheck J112 and really do have nothing there, then you are going to have to inspect every inch of the wire to find where its broken at. Unfortunately, while I can fix your board, I'm not going to be much help in finding a broken wire.

#29 4 years ago

I have an auto read function on my new meter, when put into resistance mode, and check the 1st and last pins on the J112 connector like you are doing I get 0.5 ohms resistance

When I check pins 3 and 5 I get 0.3 ohms resistance

I get 12.38voltage when on the 1 and 5 pins

#30 4 years ago
Quoted from Borygard:

This isn't factory and is connected to your 12V, remove it to see if your problem persists.
--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com

when you look at pictures from a few days ago I had the original connectors inserted during the pictures, that is the first thing I did when I had problems

#31 4 years ago
Quoted from ibjames:

I get 12.38voltage when on the 1 and 5 pins

perfect!

#32 4 years ago
Quoted from ibjames:

have an auto read function on my new meter, when put into resistance mode, and check the 1st and last pins on the J112 connector like you are doing I get 0.5 ohms resistance
When I check pins 3 and 5 I get 0.3 ohms resistance
I get 12.38voltage when on the 1 and 5 pins

Just curious, what meter did you buy and how do you like it?

#33 4 years ago

bought the Innova Auto-Ranging Digital
amazon.com link »

I like it a lot actually, nice build quality, has a wrist strap

#34 4 years ago

Outstanding! The right equipment makes all the difference. Please let us know how your repairs turn out.

#35 4 years ago

Any resolution on this?

1 week later
#36 4 years ago

No, I went on vacation, I have to order the parts

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