S+ With code 21. How do I run i/o tests?

[javajeff]

So I am helping a friend of mine who is on a very tight budget fix up her S+ machine. It's a 1991 IGT S+ Bulls-eye game.  Someone else obviously was "trying to fix it" before me. 

When I first got a hold of it, it had a broken cable on the coin comparator, which I replaced. It had a broken fuse, which I replaced. I would get '21' pretty often, but I could hit the white button on the optical board, shut the door and it'd clear.  After blowing out the dust, placing a regional coin, I found that it would work sometimes if I threw about 3-4 quarters in, one would finally register and it'd work!

I looked at the optics board, it is suppose to have 2 screws holding it, one was missing, one was stripped. I thought maybe it was out of alignment, so I replaced both the screws with new ones and wiped off the optical sensors (I didn't have my allen wrenchs with me, so I couldn't clean the LEDs off).  After this, I now constantly get the 21 error and can not get it to go away.

There is a small hole on the side of the machine and i can see the red LED on the coin comparator light up briefly when I shut the door.
I can see all 3 LEDs on the optical board lit with my cell phone.

I've read that there is some way to test these components individually, but I'm not sure how to do this. I can open the door of the machine, but she is missing the second key.  I have the service manual and circuitry manual, but if someone could give me some guidance on running the diagnostic tests on the comparator and optics, it would be appreciated! 

Can we bypass some of this for a home machine?

[Stayouttadabunker]

but I could hit the white button on the optical board, shut the door and it'd clear.

Could you show me where is this "white button" you're speaking of?

On the coin-in optics board that's located under the coin comparitor on the door panel, is a "Service Credit" button.

This is where you could put some credits onto the machine to test the machine while the door is open.

Also, there is a small white button on the MPU tray or power switch area which is known as the "Test" button.

And yeah...you can "bypass" EVERYTHING....but it wouldn't be a true slot machine right?
If you'd like to just make your machine a free play machine without having to put in coins or bills, just open the door, solder two wires to that "Service Coin" button on the optics board and run them to the Service or Change button switch under the button deck.
Disconnect one of the door optics, close the door, and you now have a "free-play" slot machine.
Basically the machine now "thinks" its door is open and in "service" mode.
Now you can add "Credits" up to "Max Bet" by tapping on the first deck button on the left....which is usually called the "Service" or "Change" button.

The "Service" button just lights up the top lamp on the candle to let attendants know you want their attention.
Long time ago, it was also used to call the waitress over that held a tray and announced periodically that she was selling "Cigars, Cigarettes, and Chewing gum".
People used to smoke a LOT in casinos....it was really disgusting....haha

oh! I forgot....here's a link to the coin-in optics test you could of found if you did a search in the IGT S+ reel games list of topics...>>>

http://newlifegames.com/nlg/index.php?topic=14723.0

Also a link to a old drawing making your machine into a "free Play" slot...>>>

http://newlifegames.com/nlg/index.php?action=dlattach;topic=4574.0;attach=10875

The topic at the time...>>>

http://newlifegames.com/nlg/index.php?topic=4574.0

[javajeff]

Thanks! I did recall seeing that post, but since my friend does not have a reset key, it probably won'twork. I might have to order one...

[javajeff]

... and I was confused on the test vs service credit buttons, they are both white.