S+ Coin drops right thru yet the Comparitor is OK

[gordy]

Coin goes roght to the tray. Comparitor is known good one,unplugged and plugged the white plug in the mother board from the power supply and plugged it back in, the INSERT COIN light is on,  the door optics do resets OK.  Sometimes when first started up it will take a coin or two and then not accept coins. Cleaned the coin in optics. Tried wedging the comparitor rake open but to no avail. Re-seated the game board. Putting in another good comparitor sometimes works for 2 or 3 coins.
   Advice?

[shortrackskater]

Have you checked your door optics?

[gordy]

yes

[Jim]

Gordy,     try this:  open the door, press the white button on the coin optic board (lower leftside bottom). if it puts credits on the machine and you can play machine then everything from that point is good.  if the cc is good, then the only thing left is the optics.

if you suspect the optics: do the input test 10_1,11_1,12_1,  door open, input test on display, cc removed, make a device that would resemble a popcycle stick, place the stick where the coin would normally go, you should see the 10_1 change to a 10_0, etc for each test.  

inspect all wiring, especially the cc plug harness (black, yellow wires) they break all the time or they are barely held in place with one strand of wire.  
if all is good with the above, one more test,  if you can remove the cc bracket (cc/coin optic/harness)  if belly door,open belly door and re-hook the assembly outside of the machine, close door and see if the led comes on the cc, and what happens when you insert coins!.
could be a simple snip of Q-2 or Q -4  and your problem could be solved.

Hope this helps

Jim

[gordy]

The plot thickens.  I snipped the Q 4, Put in a new cc harness , activated the test button successfully, and then took the whole coin in stuff from a working S+ .  About 5 coins were accepted and then no coins accepted.  So, the bad machine has known good coin optics, coin optics harness, cc harness, and cc and it still will not accept a coin.

[Jim]

Gordy,   so what you are saying ,that with all known good components the machine will still not accept a coin through the cc.

can you verify that the led is coming on when the machine is ready to accept money.   will the coin optic button put credits on the machine and can you play them.

Jim

[stayouttadabunker]

I'd like to add that snipping off the "Q4" means you might have an older CC.
Does this older CC work in a good cabinet?
Like Jim said, I wish we knew if all the swapped parts were any good to begin with?
The only way to know for sure is to test all the component units in a known good working cabinet -
that's why I have my tester "Frankenstein"...

[gordy]

The machine has all known good parts now. They came right from a good machine.

[stayouttadabunker]

You're narrowed down to the MPU, motherboard, and chips.
Might as well change out the MPU now....something's wrong...

I wanted to add that maybe the problem was a large token coin-in optics insert guide -
like those big-giant spanish dollar sized tokens some casinos use.
But you're changed out the coin-in optics too...so scratch that.

[Jim]

the reason I asked those questions was to try and eliminate somethings.   the only thing that would not allow a coin to be acceptedby the cc is that the cc is not receiving the coin lockout signal from the machine,  its actually the   24vac to give power to the cc.   

if the cc LED is on then  that would rule that out.

Jim

[knagl]

Coin goes roght to the tray.

Tried wedging the comparitor rake open but to no avail.

Hold on -- even when the rake is wedged open coins are still going to the tray???   

If that's the case, there's something physically wrong with the coin path.  With the rake wedged open, all coins (even the wrong size coins) should go to the hopper (provided they're not too big to physically fit through the optics assembly).  Compare the physical coin path of the problem machine with a known good machine -- perhaps there's something bent incorrectly under the comparator or optics that is causing coins to get diverted to the tray.

[gordy]

I dont believe it was stated that a wedged rake caused coins to go to the tray. To clarify, they go to the hopper like they should. Sorry to misslead.
  Why would a coin or two be accepted OK and then more coins are rejected all of a sudden ?  I have taken other known good comparitors from working S+ machines and the same thing happens.
  Has anyone ever found a CPU or motherboard to decide to tell a cc to stop accepting coins, and then sometimes when a different comparitor is put in, to allow a few coins to be accepted and then tell the cc again to  stop the coins being accepted ?

[edski]

Whoa! Wait! Stop! Backup!

Your first sentence says the coins fall to the tray.

An accepted coin will fall to the hopper and earn a credit on the machine.

A rejected coin will fall to the tray and not earn a credit.

When you say "rejected", do you mean coins are falling into the tray, or do you mean they are going to the hopper and not earning a credit?

“Accepted� means falls to hopper, and earns credit.
“Rejected� means falls to tray, and no credit.

It sounds to me like your optics are set for large coins, and you are using small coins.

[stayouttadabunker]

Whoa! Wait! Stop! Backup!

Your first sentence says the coins fall to the tray.

An accepted coin will fall to the hopper and earn a credit on the machine.

A rejected coin will fall to the tray and not earn a credit.

When you say "rejected", do you mean coins are falling into the tray, or do you mean they are going to the hopper and not earning a credit?

“Accepted” means falls to hopper, and earns credit.
“Rejected” means falls to tray, and no credit.

It sounds to me like your optics are set for large coins, and you are using small coins.

I agree with edski on this...
There's basically a couple of insert guides.
IGT calls them "encoders".
A small coin will miss the "B" optic eye beam most of the time.
I did some tests dropping nickels through the "Larger Denomination Encoder"
and the coin missed the "B" optic almost every time!
Quarters also missed the "B" optic beam part-time!

Here's a picture I have from a while back - one with a "guide" and the other without.
However, I don't think all your coin mechs ( You said you swapped some?) have the larger denomination encoder
so I'm suspecting something else might be wrong...>>>

[gordy]

All of a sudden it started working. Tried it 150 times !  Dont know why.

[stayouttadabunker]

  Probably some dust fuzz worked it's way out of a Coin-In decoder guide optic hole...   

[gordy]

The encoder came from a perfect working machine--same as the rest of the coin in elements.

[edski]

I'd still like to know.

Were the coins "rejected", and falling into the tray, or were they "accepted" and falling into the hopper?


Ed

[cowboygames]

Maybe he's got a bad wire on the harness and it makes or breaks the connection with the opening/closing of the door. I'd bypass the door optics and wiggle all the wires with the door open to see if it cuts in and out. Just a thought...

[stayouttadabunker]

That's possible too cowboy...but, for the time being - it's working.
And you know what they say - "don't fix it if it ain't broke..."   

Let's see if the "problem" comes back later on?