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Frequently Asked Questions about Slot Machines




If a slot machine hasn't paid out for a while, it's due for a win.

FALSE.Slot machines operate randomly at all times -no matter how many wins or losses have occurred in the past. A machine that has not paid out for a while has no greater chance of paying out in the future.


A slot machine can tell the difference between maximum & minimum bets.

FALSE.The number of coins played -or the amount of a wager -does not affect the outcome of a game. It only affects how much a player may win or lose.


Players can determine a machine's adds by counting the symbols on each reel.

FALSE.Because multiple numbers generated by the RNG can correspond to the same symbol on a reel, there are many more number combinations possible than are visible to the eye. Even though there may be only 15 symbols on a reel, there can be thousands of virtual stops.


Using a player's club card will increase the chances of winning a jackpot.

FALSE.The RNG that determines the outcome of each play is not linked to the player's club card reader. The RNG cannot tell whether a card is inserted or not, so the outcome of the game is not affected.


After hitting a jackpot, a player should move to a new slot machine. The machine currently in play is not likely to hit again.

FALSE.The odds of winning another jackpot on the next play are the same as they were before hitting the jackpot. There is no such thing as a "hot" or "cold" slot machine.


Slot machines are highly addictive.

FALSE.Research has found no evidence that slot machines lead to greater rates of gambling addiction.


Interesting Facts About the Casino World: By the Numbers


59: The percentage of Americans who consider slot machines their favorite casino game.


88-98: The overall percentage that a machine will return to players in the long run. For every $100 wagered, players might lose approximately $2-$12 over time.


1899: The year in which Charles Fey invented the first slot machine, the Liberty Bell.


30,000: The number of people employed at companies that produce slot machines and/or other casino games. These employees earn $2.1 billion annually.


2,250: The number of regulators who oversee the gaming industry. Ensuring that slot machines operate correctly is among their many responsibilities.


833,000: Approximately the number of slot machines operating in the United States.


$38.7 million: The largest slot machine jackpot ever won!


1,200: The average number of individual parts in a slot machine.


275: Approximately the number of pounds an upright slot machine weighs.



Tech Advice


S Plus

I have an S Plus machine cashing out on every pay line...

Press your test switch 3 times and you'll see your credit options. You only have

3 settings if I remember correctly...5-0, 5-1 and 5-2. I believe 5-0 is standard.

Edit: push your spin button to change it back to 5-0.


I have encountered this problem several times and for no reason these games will do this from time to time. Your option should be at 5-0 but they will still do this. What I have done is, if your option is set at 5-0, hit spin and change it to 5-1, then close the door and let it come to play. Then go back and change it to 5-0. I'm not sure why, but this has worked for me in the past. It's like the game forgets what it's supposed to do so you have to wake it up. I have ran into instances where this didn't work and had to clear the E-square on the motherboard, or just have had to replace the motherboard.



  Quality of Konami


We are getting several Konami's in a few weeks. We have never had any of their machines before. So my questions are, what do you think of them? Any reoccurring problems? Anything we should know about them before we get them?

Pretty reliable from my experience. Their technical manuals leave a lot to be desired. Not many schematics or part numbers. Just assembly numbers and breakdowns.


We have both reels and video here and the videos are pretty much care-free but the reels seem to like CRC critical errors and require a ton on ram clears.


The 2.5's are great from what I have seen.


We have 24 reels and 12 videos here and we have no problems with them. They are some of the more popular games especially the new 5 reels. The player tracking system is a whole different ball game.




Read Failure I/O Error


Anyone have an idea on the following error: Segment D800 length 8000 reloc 9000 read failed, I/O error. I believe that this is probably OS flashcard. It is on a Blue Bird I machine -Hot Super Jackpot

It's usually the OS card that goes bad, not swapping bill validators can cause it.


I would try the OS card first. WMS always has problems with their OS.



MBR Failed


Have an older Blue Bird that after 20 seconds or so on reboot, it goes into an MBR failed...I/O error. I replaced the CPU, backplane and player panel. Anyone else have input?

We, also, have that same problem. If after replacing the board itself, or the backplane and still have errors, then it might be the flash cards [OS]. Try also changing the ram card and if nothing happens, the flash cards may be bad.



550 Critical Error 13


Have a WMS 550 with a "critical error 13" display on the screen. Anyone have any suggestions? I can't seem to find this error in any of my books. For what it's worth, the game theme is "BOOM".

Data corrupted in memory. You will have to clear the MPU board.


WMS 550 rule #1: Always ram clear for any BSOD errors. There are a couple that will let you clear them with the reset switch and the menu button.



Door Open


Door open error-Spoke with WMS and they simply state that the power supply is causing the problem and that it does not cost much to get replaced. Anyone have an idea about what component on the power supply that needs replacement? It specs out, but obviously has an issue. The generic "door open S" title can "wear your team out!"

We get these a lot but I never would have guessed it was a power supply. We punch the bill validator door then use a pair of pliers to tighten the connectors on the harness behind the bill validator. That usually takes care of the problem long enough that it's no longer a big deal. It will even temporarily clear up the "I pulled the handle and now the reels won't stop" complaints.


Been down that road. MEI we thought was the culprit with the micro switch under the slide board, but after constant addressing of the lever to the switch, harnessing from the bill validator switch and the switch itself, WMS says power supply.


I have seen "door open S" being caused by the WMS CPUs creeping up. Make sure it's seated right. I've also seen a power supply cause justone door open problem though.


If you have MEI in the WMS machines, I have had the tape that is in one of the blade connectors on the bill validator harness start coming off & cause "door open S". Re-sticking the tape down clears it. I have been replacing the electricians tape with shrink tubing [won't come unstuck in the furniture from the heat]. I don't know why & can't explain it, but it works for me every time on the WMS machines with MEI bill validators.


It's the CPU. Just hit it or reset and you will be good.


When we have had the open door S it has been a CPU creeping up or the stacker switch behind the cash box needing repositioning or replacement. It has never been a power supply. Power supplies tend to cause a host of other problems along with it.


Lifting & moving slot machines


How do you lift & move your slots? I've seen the slot hand truck with a hydraulic lift but I suspect those aren't cheap. I've seen the 1/4 ton capacity hydraulic lift table for $160 & thought it would work. Other suggestions otherwise?

I've used the hydraulic lift table for 2 years. It comes to 9" off of the floor. I use a dolly to put slot on the cart.


I use a 2 wheel dolly to get them around, then have my neighbor help me lift them up on the stand. If I get impatient I'll remove some weight from the slot [MPU tray, hopper, coin tray, top glass, bill validator, cash can, etc.] & lift up myself. Try not to do that too often though.


Do not put a rubber mat on the lift, it will be hard to slide the machine to a table.


If you need to move a slot for a party, disassemble it completely, door & all. It's easy for 1 person to load & move; about half an hour for disassembly & half an hour to reassemble.


You can also use an ATV /motorcycle hydraulic lift.