EMI protection is because people would take a piezo lighter, and try to glitch the machine to get a payout. The battery backed RAM is there to store things like the random number generator output, so that power cycling the machine does not result in a predictable play. It also stores stats on payouts, and is used for the alterable elements, like winning payout percentages, odds and such. Storing the random number ensures that it will be random with each play, as it will only repeat again when the pseudo random generator rolls over fully, and that is likely clocked from the zero crossings, as a convenient clock source. Clock is also used as part of randomness, being fed into the pseudo random system as a varying input that takes 10 years to repeat itself, but which changes every second. The state of the random number generator is latched when you press start or pull the handle, the rest is theatrics, the number is set then, and is modified by the payout percentages as to which win if any is going to be allowed. Zero cross is there for generating timing pulses for lighting displays, so they can be changed at zero crossings, reducing mains noise generated by the machine, as those typically are driven by triacs to keep the power side simple and robust, and if transistors or FET's they still run off an unsmoothed full wave rectified supply. Makes the bulbs last a long time even with a lot of switching on and off. IIRC the default for most machines is to give back exactly half the money over a long period, so you need accurate tallies of payout amounts stored in RAM for this, but this can be changed by the owner via a serial interface. That lithium battery will probably last a while, even powered off, though better would be to place a low leakage Schottky diode in series with the charge side of the cell, to drop the cell voltage to 3.9V max. Will reduce capacity a lot, but the cell will last a lot longer, never reaching 100% SOC, and staying at around half capacity and 60% charge, which it will survive for a longer time. RAM will survive, probably will work and retain data to around 2V, which is long after the battery protection has disconnected. In any case, will only self discharge slowly, and there probably last around a year with no power.

Kevin, I am by no means an electronics technician, but I have tried to learn a basic understanding of how electronic devices work. Surprisingly, I was able understand what you described while fixing the slot machine board! Awesome repair video. BTW, the front door sensor you built for me last year has continued to work flawlessly! It has been close to a year since I had you build it and the battery has only dropped once, from 4.0V to 3.9V! I believe it will last five or more years at this rate! Thanks again!

Kev, thanks or sharing this one with us all. Quite informative seeing how the various security methods were incorporated into the design of the board.

I know how you feel. I get anything electrotonic related thrown at me from everyone asking me to fix it hahaha

I wonder if it would be possible to map the structure of the Virtual Reel?

How do I fix my Cherry 96 , the credit button won't work and the lights on the buttons won't work

My cherry96 buttons won't work or light up how do I fix that

Excellent

Awesome!

It's now about 3 years since this mod was made...how did the battery perform? Still recharging itself?

If the customer keeps the machine powered up 24/7, this battery will probably last longer

Looking for some help with my Lucky 8 Lines slot machine. The screen itself will not come on. I can hear everything in the background working correctly, just no picture, black like the machine is not turned on. Any help would be greatly appreciated.

What are the product details on the battery used (voltage/capacity/size) and the charger circuit board (name size etc), I'm looking to source these to upgrade mine but want to make sure I get the correct ones.

Which layout technique use in this board please elaborate .

PLEASE CAN YOU HELP I HAVE SCORPION 4 BOARD ERROR 26 REEL 6 THINK ITS BOARD BUT WHAT PART ON BOARD RESISTER TRANSITER ETC THANK YOU

Hey where did you get those schematics, I could really use them please.

Kevin I'm a long time viewer and subscriber...really get a lot out of your videos..for some.reason I always think of Leonardo DiCaprio when I see you..

Stupid question. I hit the “cash out” button with not enough coins in the hopper. Now it says “call attendant - reset during payout” any idea how to fix this??

hi mate , im in qld australia and just brought a pokie machine ( slot machine ) and it has a boot issue , prev owner played it for years and put it in the corner of his garage , if you could assist me i would really appreciate it , im about to set it up and remove the main board to take a look , i have pictures of the machine if u can help please let me know

hello if the battery is low? could that cause the machine to have a black screen but still make noises that it is on?

Do you fix fire link boards?

I’ve got a Bally black velvet copyright 2007 it’s saying SVGALIB Failed to initialize and idea what that means? I can’t find anything online.

I have a IGT S2000 Double Diamonds 25 cent quarter machine from Balley 90's in storage with no way to hook up or plug in due to no electricity. When I moved it would light up but the reel would not spin. What are your thoughts on a fix? After watching your video I do remember when my husband was alive he fixed it and we ordered a board from e-Bay and everything worked and then we would shut off when not playing it and sometimes just kept it on. Do you think since it was just left on, it might have just drained the battery? I don't know how to find the back board on my machine. Maybe I should hire someone. If so, how do I find a slot machine tech?

Afternoon. I have a ballys black gold wild quick hits machine it gets halfway through the loading process and will not load the top screen. Not sure how to change the battery or what to do. Would be happy to pay you if you help get it fixed

Hi , i got a bally slot machine serie 5000. I get error 5.5. Can Someone help me??

how much would u charge for your services pls?

could you install an NV ram and make a battery unnecessary?

i wish i was that smart

So the designer put in a EMI circuit to prevent cheating...can you dig deep into how this logic board controls each payout lol

Great Video, Kevin, Thanks On a second note: I have a Bally 5500 and can hear the coins dropping into the hopper but it won't register the credit. The Comparitor and Coin optics are fine and I'm getting No Error Codes... Anyone have any ideas?????

I need someone to check mine I think the on/off switch is no good I will pay to have it fixed

Maybe you can help me ... i have a Ballys Roaring 20's Slot Machine from 1993 ... it has a Cash Box but i do not know how to open it ... there is a door on the side of the machine thats opens next to the bill acceptor but where do i get the money out of???

hi we're a pcb manufacturer,can you pls put our video and website link on your youtube channel,we can pay you for that,if you're interested,pls leave us your email!

That's a dangerous solution, the battery goes dead if it's below 2.8 volts and can go it to flames or explode if will be charged with 500ma from zero and force the battery to 4.2 volts. I would not use that kind of solution with li-ion or li-po.