Slot and "Entertainment" Machines
A few years back I was given one of those rather nasty tabletop video slot and poker machines. Some people call them 8-liners and others call them Cherry Master machines. In a nutshell it's the bare minimum for video gambling and it seems when you don't find them in the back corner of a seedy bar you find them by the dozen at makeshift gambling parlors in the old shipping container behind the seedy bar. Anyways for as novelty as it was and as humorous as the video test mode was where it just displayed sleazy naked women from the strip poker mode I really wanted something more genuine for a slot machine.
Now I work for a specific organization who services more modern slot machines. Can't say who or what I service but modern slot machines are really in no way anything fun once you open the door. Just a computer with LCD displays, electronic buttons and a ridiculous number of security and anti-cheat systems. Stuff that gets a complete pain to even get back to an idle state if the battery goes flat. I kinda wanted something a little more.....authentic? I know there are really old machines from the likes of Mills and others. Large all-metal mechanical contraptions but be damned if I could buy a modern slot machine on the surplus market for less. A relatively clean and oiled fruit machine was sitting between $2000 and $3000.
Then after I started to be a bit less picky I started to find Bally's line of machines from a few decades earlier from the 60's and 70's. Now I was starting to find something both attractive and cheap. I finally settled on what was believed to be a mid-60's Bally 742A machine that the local Craigslist had for under $500CAD. It was a gamble (pun) on its own though as I bought it sight unseen and just an assurance "all the lights turn on and it used to work but the reels don't lock now". I mean, what, could go wrong with a bit of new grease, right?
This is where I took my first step down the rabbit hole.
This particular machine according to the previous owner was installed at the Sands Hotel and Casino, however on first look it shows the branding hallmarks of being from the Mizpah Hotel in Tonopah, plus a Mizpah book of matches stuffed into one of the door hinges and a service card with the last entry from 1982. Previous owner said the machine had been in the family and the hotel had closed for a period in the early 2000's, so at least that held water.
I was expecting this to be Electromechanical. These machines relied heavily on complex mechanical assemblies to start and stop the reels plus an army of relays, solenoids and contacts to make everything else operate. Typically problems developed when a relay came loose or the grease dried out.
Unfortunately this where is where I discovered a company called Summit Systems. In the late 70's or the early 80's this company sold retrofit kits that rebuilt the older electromechnical machines into electronic machines. In addition to new solenoids the original wiring was replaced and a primitive computer took over.
The mechanical aspect however was still there. You pulled the handle, the reels would spin freely on bearings and the computer simply ran the game played in its head and knew where everything was on the reels. When it found the index mark matching the electronic game played it locked the reel and either paid out or told you to insert another coin. It however needed a battery to remember its operating state should the power fail and keep record of things like how many coins were in the hopper and how many coins had been paid out. That battery had not been removed.
This was partially why the machine stopped working. The microcontroller was not operating. The other was a perished rubber seal in the air piston which regulates the strength of the handle pull, but that was easy to fix. This CPU board was not.
The reason I wanted to avoid an electronic slot machine was they can get expensive to repair really fast and are much more complicated devices. I have only managed to find one company that still sells parts and some service support for these Summit converted machines and to scale the prices a phone call alone was $40 for the first 15 minutes, plus an extra $2 for each additional minute. I had to repair this on my own and hope that EPROM had not failed. the VAPS forum also proved unhelpful.
As it turned out the battery damage did less damage to individual traces and more to the through-hole via connections that connected one side to the other. Repairs consisted of replacing a dozen vias, repairing two broken traces, replacing the sockets for the CPU and EPROM, replacing three transistors with modern 2N2222's for the three seven segment displays on the front of the machine and simply putting every other IC in a socket because if I had gone this far why not go all the way?
Remember how earlier I said that a flat battery will make machines not work and this one needed one to retain a small amount of things? Thankfully because of the age of the machine it was not that new that a new battery meant reconfiguring everything. Paytables, odds and denominations are hard-coded to the EPROM. This machine WILL work with a missing or flat battery, it just won't remember certain things. A good modern repalcement however is a 3.6V rechargeable battery pack from a cordless telephone. It's at least twice the rated mAh of the original battery and it's easy to put a piece of velcro on it and hide it somewhere where it leaking won't cause more problems.
Of course, problems persisted. Most of the indicator lamps would filcker if you so much breathed on them and you would have weirdness from the LED display and it seemed everything else in the machine. Because the battery had leaked and evaporated some of its chemistry over the last few decades the inside of the cabinet had a peculiar light and fluffy corrosion on everything that was not painted. The hopper and reel/control assemblies plug into the cabinet with massive Jones plug connectors. but the bulbs used the standard brass sockets. Everything had to be burnished by hand with emery cloth before it would work reliably.
Finally it wasn't so much a repair but a modification.
You blasted americans have not yet messed with the metal content of your nickels. Even a modern one will work. In Canada however most banks cannot order in foreign coinage so all we get to request in bulk are canadian nickels. Problem there however is after 1999 we went from pure nickel to a steel slug plated in nickel. Anything that does not know of this change sees them as counterfeit. This machine is no exception as you would drop a nickel in and you would find it stuck to the magnet in the coin mech. I had to remove the magnet from the coin mech before it would stop complaining, then bewilder the clerk at the bank when I came in asking for $40 in nickels.
Anyone else here have a corner of their place with a slot machine in it?