Door optics and mpu

[anchorbru@outlook.com]

I have a 2 coin 4th of July I am working on.  Below are my symptoms and steps I have taken to narrow down the issue.  Over all issue is my door optics don’t work.

1) swapped whole Mpu into working machine and it does some funky things ult8mately getting stuck in a 3100 after putting hopper back in.  Opening and closing the door does not resolve.
2) swapped known good out of good machine and ran in 4th of July machine and everything works as advertised.
3) original board in 4th of July, ran door optics test and I have 13 0 open and 13 1 solid when closed, everything is aligned.
4) red out connectors for optics, both reading 9vdc, led side should be reading 4vdc

I am convinced the board is the culprit.. what on the Mpu can I check, read out or replace to fix this issue?

[Tilt]

3) original board in 4th of July, ran door optics test and I have 13 0 open and 13 1 solid when closed, everything is aligned.

That's what it should be, so why do you think it's bad?

[anchorbru@outlook.com]

No it should be when the door is closed you get alternating 1/0 very swift.  I get a solid 1

[Tilt]

You're correct.  That's what I get for reading the manual instead of doing it on the machine.  The book says it changes state, but on the machine it does alternate when closed like you said. 

What's odd though is it does change state for you when you close the door, so the optics have to work and the MPU sees it close.  Are you using the same SP game PROM on both boards? 

[anchorbru@outlook.com]

Yes. Same sp game prom.  It is weird….  From what I understand is that the led, door side of the optics pulses its light very fast……this is why when you read the plug it reads 4vdc and not 9 like the receiving end, cabinet side…….but this one is reading 9vdc at the door……. I believe I have done everything to prove that it is the Mpu, I just need to know if there is a diode, capacitor, xenor, thyristor or something I can read out and replace to fix this without replacing the board.

[jay]

The door optics are running a pulse pattern,  they do this for security.
One of the famous cheats was to use a high intensity light pen to fool the optics into thinking that the door is closed.
I seem to remember hearing that they would break or shim he belly glass door and then release the door from the inside.
I have always wanted to see this in action as I have a hard enough time opening with a key.....
If you use a light pen with the pulse style optics you would get an error right away.
If you want to see the pulse you can use a digital camera/phone and point it at the emitter and you will see the optic pulse, otherwise invisible to the naked eye.

The door open/closed self test shows 0 for open 1 for closed - you won't see that change.

The other hack was to shine a light pen up through the coin tray - this would blind the hopper optic so coins passing would not be counted, but still fall to the tray.
In this case you had to be careful of the timing as if you kept it constant the hopper would error out thinking it was empty.
The security fix was more mechanical by putting both a lip on the hopper and a plastic barrier in front of the optic.

[anchorbru@outlook.com]

Still not getting my answer to the question is there something in the board that has failed that I can replace.  I am convinced it is the board.  There is something on there that controls that pulse.

[jay]

My post was more about confirming the 13-0/1 state and some inane trvia to fill the white space.

This thread discusses possible issues with the cashcan optics that can give similar symptoms to what your seeing.
http://newlifegames.com/nlg/index.php?topic=32341.msg171771#msg171771

I am not aware of any socketed components on the MPU that control the door.
The optics have molex'es on them - have you tried swapping from your other machine ?

I would consider running a clear chip through the machine ?

I know people who have had bad MPUs have sent them to KLAR to be repaired.

There should be a S+ electronics manual in the download section that would have the schematics if you want to attempt your own board repair.



 

[anchorbru@outlook.com]

Thanks Jay, yeah I already went through that posting along with at least 10 other…..

Fortunately I have two other working machines and have swapped every configuration I could think of between the three machines and that has pretty much led me to believe it was the MPU.  I have been meaning to become a contributing member for a while…..guess it is time so I can get the schematics.  I have done board repairs on other things so I am not worried about doing that. Where I lack in knowledge is finding the thing that needs repaired…..was hoping someone could guide me in the right direction.

[Tilt]

Thanks Jay.  Should have know it would be related to cheating

Here's a troubleshooting guide for constant door open  It may be helpful?