Error Code 21 on IGT Plus

[Amg16]

Hi Everyone,

Apologies if this has been answered in any other forum post, but I've scrolled through everything relating to Code 21 and can't seem to find any threads that cover my specific issue.

I bought two IGT machines yesterday, and while one is working perfectly, the other has Error 21. In the attached pictures, the top comparitor is the one working perfectly, and the bottom one is the one I'm having issues with. As far as I can tell they're basically the same model with some minor differences. What's odd is that neither of these comparitors appear to have a sample coin. Rather, the working one is using a type of rubber stopper for the slider, and the one that isn't working doesn't have anything.

I included it in one of the photos but trying to use a sample coin for the error code comparitor makes the slider move too far over so coins get stuck in the entry slot (im using quarters). I also can't fit a quarter into the slider area where the rubber stopper is. Has anyone seen anything like this and have any suggestions? I assume the easiest thing would be to try and find some type of duplicate of the rubber stopper but I'm not sure where I'd find something like that. Thanks for the help!

EDIT: just to try it I put the working comparitor into the machine giving me problems, and error code 21 is still not going away after using the reset key, opening and closing the door, etc. Although I still find this machine's comparitor to be a problem, I wonder if anything else is going on?

EDIT 2: This is as of end of day 7/15, figured it would be easier to update with a video
https://youtu.be/DJlF1ExfyjA

[Amg16]

Figured I'd add a photo of the inside door of the one giving me issues, comparitor obviously removed but all wiring seems fine

[sixcardmark]

Error 21 is coming the coin-in optics board under the CC. It needs cleaned, lined up properly, or replaced. It also may have wrong size coin guide. The CC must have a sample coin to compare to, that's why it's called a coin comparitor.

[Amg16]

Hi, thank you for the insight! After typing this I will remove the optics and adept to clean, however I'm kind of confused on your second point. The other CC doesn't have a coin and seems to be working fine, and I'm unable to insert coins through the insert slot when I use the quarter as a sample coin?

[sixcardmark]

The one with no coin has probably been modified so it can't reject ANY coins.  It will probably accept a nickel or token too. https://www.youtube.com/watch?v=r27kTXjEAJ0

[Amg16]

Hi, it looks like you're right! The working one does accept at least nickels as well. I guess that brings me back to my original post and question with the picture, because I still can't get a coin to go through the slot when the sample coin is set to a quarter? I've tried to loosen the screw on the entry slot so the rubber stopper gives way easier, but that hasn't worked either

[sixcardmark]

Be sure to get that nickel out of your hopper before it jams it up.

[Amg16]

I'll likely update the main post as well but figured it would be easier to just throw up a video

https://youtu.be/DJlF1ExfyjA

[sixcardmark]

There is a tiny white button in lower left corner of coin-in optic board.  It should ding and give a credit when you press it and the spin button should lite and let you spin the reels.  There is also a coin-in optic ABC test. Refer to the flip cards for instructions.  Check all the connections on the orange harness, it could be the problem.  Sometimes just tucking them back will clear the 21.(open and close the door to clear)

You may need new CC's for both machines and a new optic board.  Is that one machine still a barcrest?

[Amg16]

Sorry don't mean to reply exclusively with youtube videos hahaha just finding it easier for all of this

https://youtu.be/eRelZGg75F4

A couple points I didn't bring up in the video worth mentioning:
-For whatever reason, taking the cylinder weight off the comaparitor is making the quarters go through fine. If that weight is mandatory I can put it back on but found that interesting
-I'm not sure what differentiates a barcrest from one that isn't, if there's anything I can check for that I'm happy to do so!

[sixcardmark]

Yes leave it off.  Machine with speaker in tray was s+ barcrest or has s2000 tray.
Optic test:

10 1
11 1
12 1

They will go to 0 if they are blocked by a coin or other object. As as the path is clear they go back to 1.
a 0 showing all the time in test means check for blocks or install a known good set of optics.
It could be as simple as a bad optic or loose wire or connector in the harness. 

[Amg16]

Thanks for the continued advice! I should be able to try testing those numbers tomorrow, just to clarify can I test all those numbers with the Test button exclusively or do I need to use the reset key at all?

[63mini]

Amg16,

 What denomination are your games?  The comparators you show in your photos have a larger weight and look like CC-33?  Those are for larger coins like a $.  If someone didn't convert these properly then you may have the wrong size optic spacers too. Lastly, what is the denomination of the hopper?

[Stayouttadabunker]

You have a more serious problem.

In your last video when after you closed the door and rebooted the MPU, the 1st reel spun downwards a single symbol and stopped.
Hopefully the problem is just the wrong SP chip and not an MPU failure.

I need to see a clear photo of the chips you have installed in the GAME and REEL sockets.
That reel behavior is telling me that you may have the wrong SP installed in the GAME PROM socket.

Another thing I noticed hich may or may not be important is that the reels are numbered backwards....the 1st reel should be on the left.
But it IS indicative that someone was messing with the reels before you got that machine.

Also, do you have a small blue volume dial on top of the MPU?
If not, then you have a 16Mhz MPU...that only works with certain SP chips.

SInce you have two machines, you need to get at least one set of known working coin-in optics and a good CC.
The CC's you have now can be used but you'd need to remove the weight pawl that's on top.
That weight is much too heavy for quarters.
A single small flat headed screw removed is all you need to to do to take it out.
You don't really need it and the quarters will go thru much easier.
I forget offhand right now which way you turn the coin sensitivity potentiometer dial but using a small Philips screwdriver, and turning the dial fully clockwise or counter-clockwise will allow the comparitor to accept even Canadian quarters.
The correct setting of the coin sensitivity dial on the coin comparitor normally for U.S. quarters is turning the dial all the way fully counter-clockwise, then turning it a quarter turn clockwise....it gets you in the ballpark so that the comparitor ONLY accepts quarters.

[Amg16]

Hi, hope to answer both of your follow ups here!

I tried repeatedly pressing the test button and got to a 10-0 code with the Coins Inserted label showing a 1, camera was having a hard time capturing it but there is a 1 there. As far as I can tell no matter how many times I hit the test button I don't get to an 11 or 12 in Winner Paid at any point.

I have taken the weight off of the CC and quarters are now falling through to the hopper without getting stuck, and a quarter is inserted as the sample coin. For the hoper itself, I'm happy to check if there's a more proper way to look for denominations but the quarters fit into the bottom wheel fine and it appears to be the original IGT hopper.

I have attached photos of the entire MPU and a zoom into the chips for Stayouttadabunker. As far as I can tell there's no dial on the board anywhere?

[Amg16]

To give more contexts on the codes, the sequence as I hit the test button is
-10-0 with 1 for coins played
-10 with 2 for coins played
-50 with nothing showing for coins played
-8888 for both winner paid and credits, 8 for coins played

I also attached a more clear video of the forward jolt before 21 pops back up, this instance was a bit weirder because they're only usually moving about 1/4 of the visible reel with door closed most of the time, they moved much more on this one

https://youtu.be/MNp5AMx6Sr8

Just to cover everything also posted some more photos of the CC and optics now with the weight removed

[Stayouttadabunker]

okay...you have a 10mHz MPU and your chips might be okay but your reels are NOT supposed to do that after booting up or closing the door.
There's a blue plastic volume dial on top of your MPU....if you look at the radio crystals, you'll also see "10Mhz" imprinted on the silver canisters.

Turn the power switch OFF.
Can you carefully pull up and out the SS Reel chip from it's socket?
Use a small flat screwdriver and try to work the body of the chip upwards as flat as possible.
When you get it out, take a look at the chip legs.
Starighten out any bent leg with a pair of nail tweezers.
Then slowly re-insert all of the legs back into the socket.
There will be an indentation on top of one end of the chips' body.
That indentation should be oriented with the notch imprinted on the MPU circuit at one end of the socket.
That chip ONLY goes back on that way.
Make sure you DO NOT fold any chip legs underneath the chip 's body.
Put the MPU back into the enclosure and turn back ON the power switch.
Closely observe the reels action.
They should spin back to their last positions before you turned off the machine.
If so, you may be back in business, close the door and see if quarters get accepted.
If your display lamps are working and not burned out, the reel glass SHOULD say "Insert Coin"...and when you do, the other lamp should light up that displays"Coin Accepted.

I wish you had another coin-in optics board to try.
That one in your last Reply ( Photo ending with 191550), actually looks burned out.

[Amg16]

Hi everyone, bit of an interesting update:

I decided to move the entire CC and optics bracket to my working machine, and move its bracket to the Code 21 one. Surprisingly, the working machine still works fine, and the CC/optics combo that works fine in the other machine is still not clearing code 21. I will be trying the reel chip idea shortly, but I guess this means we can rule out optics as the issue?

[Amg16]

Just tried to adjust/re-install the slots chip and it seemed to have no effect. Although the brackets were a bit bent in a couple spots and I straightened those out, running Test after rebooting still led to the small jolt forward and code 21 reappearing. Hopefully at least now that I know it's not the machine's optics at fault we can narrow it down a bit?

[Amg16]

Hi, posted a couple of video updates

https://youtu.be/tSVQWIUlKX8
https://youtu.be/5HpAqGY6gFA

The summary is that I've confirmed both comparitor/optics and their white test buttons fully function on the working machine. It appears that SOMETHING in the machine with code 21 is not powering and/or communicating with the optics and CC properly?