Wiring Harness

[spisi]

So, I'm looking to buy this but it has no harness...would it be easy to find one? What should I be searching for? Molex 6 pin harness?

[Howard_Casto]

Hmm.... that's a strange number of pins.... That should be a regular optical gate setup which would only need 4 pins, power, ground and two data lines.  The only thing I can figure is it uses 4 data lines somehow?

[PL1]

So, I'm looking to buy this but it has no harness...would it be easy to find one? What should I be searching for? Molex 6 pin harness?

It might be a bit tricky.   

Search terms like "12 contact female PCB edge connector" are likely to be useful.

This looks like it might be the right connector, but there are no specs like board thickness or contact pitch (center-to-center distance between contacts) listed.
- E-mail twistywrist a pic of the optical board, the board thickness, and the contact pitch -- they should know if it's the right connector.

https://www.twistywristarcade.com/edge-connectors/1110-6-12-edge-connector-solder-tail.html?



If that doesn't work, looks like Mouser has a pretty good selection of PCB edge connectors.

Hmm.... that's a strange number of pins.... That should be a regular optical gate setup which would only need 4 pins, power, ground and two data lines.  The only thing I can figure is it uses 4 data lines somehow?

This appears to be the same wheel and optical PCB from a Top Speed cab that OP was asking about earlier here.

Two of the edge connector contacts are unused per the Top Speed manual here, bottom of pg 16.


Scott

[spisi]

I am the OP (don't know what that means lol). Now that I'm home I can upload better pics. I have one, I'm trying to get a second one, but that one is missing the harness...
The wires are ground, power and two data wires

[PL1]

I am the OP (don't know what that means lol).

OP = original poster. (the person who started the thread)   


Scott

[PL1]

Based on that second picture, it appears that the pitch is 0.156". (3.96mm)

When you use that in the search terms, it looks like Digikey has a number of good options.   

https://www.digikey.com/products/en/connectors-interconnects/card-edge-connectors-edgeboard-connectors/303?k=0.156%22%20edge%20connector

Choose filters for gender (female), pitch (0.156"), number of positions (12), termination (solder eyelets), and check the Stock Status "In Stock" checkbox then click on the "apply filters" button.

That should leave you with five good options, assuming that the PCB thickness is 0.062". (1.57mm)


Scott

[spisi]

Thank you Scott! 

I went to the site, I ended up with 9 options    Here is a picture of the actual harness.

[PL1]

As long as the PCB thickness and pitch match, the double-sided 12 contact edge connectors I saw at Digikey should work fine in place of the original single-sided 6 contact connector.

One trick I forgot to mention is to write the words "solder" and "component" on the long faces of the connector so you know which side is which when you connect it to the optical board.   


Scott

[spisi]

So, any of these five connectors will do the trick? What are the differences between them if any??? Thanks.
https://www.digikey.com/products/en/connectors-interconnects/card-edge-connectors-edgeboard-connectors/303?k=0.156%22+edge+connector&k=&pkeyword=0.156%22+edge+connector&sv=0&sf=1&FV=29%7C346497%2C88%7C80383%2C89%7C12091%2C536%7C7665%2C589%7C405014%2C1514%7C249730%2C-8%7C303&quantity=&ColumnSort=0&page=1&stock=1&pageSize=500

[PL1]

So, any of these five connectors will do the trick? What are the differences between them if any???

Yes.  Assuming that the optical PCB is 0.062" (1.57mm) thick, any of those five should work for your application.
- If you don't have calipers or feeler gauges to check that measurement, compare it to the center-to-center distance between adjacent legs on an IC. (0.1")

Far as I can tell, the very minor differences between those connectors are not important for your application.


Scott

[PL1]

Just noticed that the PCB shown in the first post is not the same as the one shown in reply #3.

Looks like the one in the fist post has two transistors instead of an 74LS14N IC and it also has a key slot on the PCB edge.

The first post PCB is probably an older version of the PCB in reply #3.
- Should be the same measurements and pinout, but it would be a good idea to verify that 5v/ground/data lines are on the same contacts before applying power.


Scott

[spisi]

OK, the second steering wheel has arrived! So, I hooked it up to the existing harness and you guessed it, it doesn't work. I thought they were identical, they look the same except the circuit board (go figure).
Can someone (Scott) shed some light on where I go from here. Here's the two pics.

[PL1]

it would be a good idea to verify that 5v/ground/data lines are on the same contacts before applying power.

Hope you didn't fry anything.   

I thought they were identical, they look the same except the circuit board (go figure).

Grab your multi-meter and cell-phone/digital camera.  It's time to reverse-engineer the optical board.

There are two pairs of optical circuits like this simplified diagram.
- Two IR LED circuits (left) with two connections each. (5v and ground)
- Two photodiode circuits (right) with three connections each. (5v, ground, and encoder)



First thing to find are the two IR LEDs.

You may need to pull the encoder wheel so you can see the IR from a lower viewing angle like this when you check the LEDs.   



Based on this picture, looks like the LEDs are between the screw heads.
- If I had to guess which edge connector contact is which based only on the board layout, I'd guess, from left to right in this pic: ground (or 5v), no connection, data line, data line, 5v (or ground), no connection.



Set your multimeter to diode check and clip one meter lead to the bottom lead of one of the brown-body resistors and the other meter lead to the right lead on the lower horizontal tan-body component. (resistor or diode?)
- If you get the correct polarity, LED check mode will dimly light the IR LED.
-- You will probably need to use your cell phone camera to see the LED since IR is outside human eye visible wavelengths, but is within the visible wavelengths of the camera.
- If the LED is lit, check the other LED.
-- If one LED is good and the other is burned out, the cursor will move back and forth one step when you turn the wheel -- you'll need to replace the optos.
- If the LED isn't lit, swap the red and black meter lead connections (polarity) and check again.

Once you confirm the connections that light the LED:
- Trace from the red lead connection through components to the edge connector -- that's 5v.
- Trace from the black lead connection through components to the edge connector -- that's ground.

If neither polarity connection works, either the LEDs are under the encoder wheel or you fried both LEDs and need to replace the optos.

Once you've got the 5v and ground connections sorted, that just leaves the two data lines.
- If you get those backward, the wheel will move the cursor in the opposite direction expected.


Scott

[spisi]

Wow! This is way over my head! I don't have a multimeter either (I think my Dad might). I'm gonna read this 10 more times and try to test it out....might take me a while. I'll try my best!

[PL1]

Here's a video showing the same type of LED check described above.



Look for the diode symbol on the multimeter.




Scott

[spisi]

Does the key slot in the edge connector tell us anything?

So, without testing but examining the photos more closely. I'm guessing (left to right) 5v - NA - Data - Data - Gnd - NA.
The original setup is: NA - Data - Data - NA - Gnd - 5v.

So looks like when I connected the old harness to the new board I supplied 5v to a NA slot. So hopefully I didn't fry anything! (crossing my fingers).

Would this be easier to just buy a new optical board that come with their own harnesses?

A co-worker had a multimeter but it didn't have the correct symbol/setting 

"Set your multimeter to diode check and clip one meter lead to the bottom lead of one of the brown-body resistors and the other meter lead to the right lead on the lower horizontal tan-body component. (resistor or diode?)" Is this correct?

[spisi]

Also, if and when I figure that out. It seems like tracing it back would be impossible.....

[PL1]

Does the splice in the edge connector tell us anything?

The gap tells us that the original connector was "keyed" so the PCB would only go in when the connector was in the proper orientation.
- Since this optical board only uses contacts on one side, you can safely use an un-keyed two-sided connector.
- Consider writing "component" on the component side of the connector and "solder" on the solder side to reduce the chances of connecting it backward.
- That wouldn't cause damage, but the connector contacts would be on bare fiberglass instead of the PCB contacts so nothing would work until you flipped the connector.      

So, without testing but examining the photos more closely. I'm guessing (left to right) 5v - NA - Data - Data - Gnd - NA.
The original setup is: NA - Data - Data - NA - Gnd - 5v.

So looks like when I connected the old harness to the new board I supplied 5v to a NA slot. So hopefully I didn't fry anything! (crossing my fingers).

5v to a not connected contact is the best possible wiring mistake to make -- no harm done.   

Would this be easier to just buy a new optical board that come with their own harnesses?

If you find a source for a replacement board, it probably won't come with a harness since most customers don't need it.

A co-worker had a multimeter but it didn't have the correct symbol/setting 

A multimeter is a very useful tool for this hobby.

Buy one, even if it's just a Harbor Freight el-cheapo like this one.

There are quite a few auto-ranging meters on Amazon in the $20-$35 range.

I also recommend getting a few test lead accessories like alligator clips, micrograbbers, etc.
- This kit looks pretty good.  https://www.amazon.com/Electrical-Multimeter-Alligator-Probes-Professional/dp/B074L1NXRX/

Also, if and when I figure that out. It seems like tracing it back would be impossible.....

On a small board like this it's really easy, just do what Dorothy and Toto did:  Follow the yellow brick road. (PCB traces)   


Scott

[spisi]

LOL! Some of those roads intersect and such don't they? Well, anyway I'm going to get a tester and we will go from there. Thanks for all your help! I'll keep posting!!!

[spisi]

OK, my neighbor has a multimeter. So, I tested everything, I got numerical readings everywhere, doesn't seem right. Some readings were 1750-1800 some were 550-650, and one was over 1900. Never got the LED to light up... . I was using my iphone in video mode, is that correct?

[spisi]

I realize that the two inner legs of the LED's are positive, and the outer legs are negative...so based on that, and following the yellow brick road, which I'm not so sure of since there are many forks....(I don't remember there being forks in the movie LOL)....I'm confirming my original assumption (uh oh) that the left most slot is the power (crossing fingers). Still would like to see that LED light up though...

[PL1]

I was using my iphone in video mode, is that correct?

That mode should be good.   

You can test if the camera is filtering the IR by looking at the IR LED on a remote control while pressing a button.

Never got the LED to light up... .

It could be that the LED is dimly lit, but you're viewing it at too steep an angle to see (10-15 degree beamwidth is common for these types of LEDs) or ambient light in the room makes it hard to see.

  or

It's possible that the components I thought were the LEDs are actually the photodiodes.
- If so, the LEDs are under the encoder wheel.

Either way, pull the encoder wheel for a better view.


Scott

[spisi]

OK, took the board completely off. I'm 99% sure I figured it out (still no lit LED) see pics.

[PL1]

One other way to tell the difference between the anode (+) and cathode (-) is the flat spot on the cathode side.




Scott

[spisi]

Both sets look perfectly round to me...

[spisi]

Can I test the card right at the edge connector?

[PL1]

Can I test the card right at the edge connector?

Not with a multimeter.

The resistors will drop too much voltage and the meter doesn't provide much current.

Picture trying to shoot a squirtgun through a 20 foot garden hose -- there's not enough water pressure (voltage) and not enough water (current) for it to be effective.

To test the diodes you need to place the meter leads either directly on the diode leads or place them where there is nothing but leads/traces between the meter and diode leads so there's no extra resistance. (shown in this picture)
- This is where accessories like micrograbbers and alligator clips come in handy.   




Scott

[spisi]

ok thanks Scott, I'm waiting for the edge connector to arrive...

[spisi]

You're gonna laugh....I had time on my hands so I taped the wires to the contacts  in the order that I thought would work. Alas, it did not.....So I then switched the 5v and ground, and of course that did not work either. So either the board was DOA or I killed it  .

I searched online for replacements but did not see anything that would look like it would work. Is this board repairable? Or do I need to hunt one down?

[Howard_Casto]

Nothing on that board is unique.... you can rebuild the entire thing if you so choose.... just order the parts.  I will say this though..... taping the wires to the contacts may not work depending upon how you did it.

[spisi]

Well my edge connector should arrive soon, I'll try it with that and see what happens, but I have a feeling it's not gonna work  .  Is there a company that can rebuild it?

[PL1]

You're gonna laugh....

*Narrator* Scott didn't laugh.   

Is this board repairable? Or do I need to hunt one down?

The board and resistors are in great shape.

The BC237 (BC237B?) transistors, LEDs, and photodiodes need to be tested/replaced by someone who knows what they are doing.
- This should be fairly easy for someone who does arcade PCB repairs.
- The transistors are on Amazon.
- The LEDs/photodiodes can be replaced individually and look like they are standard size, but I'm not sure about the specs.

When you contact someone about doing the repairs:
1. Send them pics of the board.
2. Mention the the "IME Firenze" markings and that it is not the same optical PCB/pinout that is in Top Speed.
3. Request testing/repair of the board, a pinout, and clarification whether this board is an "active low" or "active high" device.


Scott

[spisi]

OK, thanks Scott will do!

[spisi]

I found someone who will take a look at it, hope he doesn't charge too much. What should I expect to pay for something like this?

[PL1]

I found someone who will take a look at it, hope he doesn't charge too much. What should I expect to pay for something like this?

Worst case, $15-25 for transistors/LEDs/photodiodes/shipping, plus whatever his time and experience are worth.


Scott

[spisi]

Yea, so this could cost me over $100   

[PL1]

Only if he is seriously ripping you off and charging $75/hour.

The LEDs and photodiodes can be tested without removing them from the circuit.
- If that takes 5 minutes, it's because he spent 3 minutes looking for misplaced meter leads.   

The NPN BC237B transistor might need to be removed from the circuit for testing.
- Datasheet here shows the collector, base, and emitter pinout.




Scott

[spisi]

OK............brought it to a reputable guy, he tested it, said it was good to go...(huh)....brought it back home hooked it up with my edge connector....and....of course it did not work
I'm ready to kill myself (not really)...so aggravating. So I thought about it for a bit, the guy tested it in front of me, power was good, ground was good. But, never tested the the two signal outputs. I looked closer at the board and saw this...

[spisi]

Looks pretty bad, the one on the left is the ground, but that still checked out ok, the one on the right is one of the two signals. I bet that is the issue...  I know that if one of the two signals is not connected, you get no response at all. Please, please, let this be the problem. I'm a noob and don't solder but I'm bringing it back to the guy and have him fix both of those joints.  I'll keep posting.  All this so I can play two player Super Sprint 

[Howard_Casto]

How much is this guy charging, because I'm pretty sure you should be able to pick up a soldering iron at walmart and handle this yourself.... Let it get hot, touch the spot and add solder if needed.