Really LOUD buzzing at all times

[knagl]

Greetings.

I've read some of the other threads -- I saw a lot of "install some volume controls!" ...I'm not positive that's my issue, though.

I just bought this machine -- my first Pachi. When I plug it in I can hear the power transformer humming. It's not too loud, but I can hear it in a quiet room. When I turn the machine on, however, the speakers buzz like there's no tomorrow. I mean, they're LOUD!!

There are three speakers -- two upper ones and one lower one (bass, I believe). If I unplug the speakers, the game is very quiet. If I plug in any of the speakers, that darn buzz is there and is overpoweringly loud.

Is this really "normal"? I can't imagine there was that much buzz when it was in use in its prior life. I'm willing to try volume controls, but I'm wondering if I perhaps have a different problem (like perhaps I need a different power supply?).

Any thoughts? Thanks in advance.

Edited to add:
There is a three-position volume control as part of the machine. In all three positions the buzzing remains the same (while the game sound does increase or decrease, depending on the setting).

[teqkng]

Bad or improper power supply. easily available from stealth or GAKU

[knagl]

Bad or improper power supply. easily available from stealth or GAKU

I am really a n00b when it comes to this stuff. Where would I find stealth or GAKU?

There's a local (to me) store that sells power supplies (among other random things) -- if they had a PS that had an output of 24vac, minimum of 5a (which is what appears to be in there now, unless that's wrong and the root of the problem?), I could just use one from there, right? Do those specs sound right?

Thanks again in advance.

[Chrisdice]

Thats just the famous Sammy Squeal . Most older Sammy models have this issue some worse then others. My King Camel was bad at first too. Set the switch to low and Install Volume controls and you can almost eliminate it, almost.

[knagl]

It's not so much of a squeal as it is a buzzing that overpowers the normal game sounds. Is that in fact the "Sammy squeal"?

Edited to add:
This machine does NOT have an LCD display, which from what I'm reading is a general culprit for the 'squeal'. It does have a small red LED display to the right of the reels that occasionally displays crude animations, but it does not have an LCD "video" display at all.

[teqkng]

If it is noticiably humming even with the machine off there is something amiss with the coils in the power supply, I would replace it. Make sure you are at the same cycle rate A/C. The A/C current used overseas is commonly oscilated at a different rate than in the US and can cause the hum issue, I believe the two standards are 50 and 60 a power adaptor designed for the wrong standard can cause many issues. I dont have a ready explanation or analogy at ready for this one so one of my fellow technonerdies is going to have to help out.

[birdbrain]

ground the machine also

[knagl]

To be clear, when I plug in the machine there's only a slight hum coming from the transformer (that steps it from 120vac to 24vac). No sound from the speakers. When I turn it on, that's when I get the loud buzz from all the speakers.

What part of the machine should I be grounding (ie. where should I attach a ground wire to)?

Here's an interesting development:
The buzz goes away when the hopper is running.
I pressed the "cash out" button to have it spit out my remaining credits, and sure enough the sound was normal (great!) while the hopper was churning away. As soon as the hopper motor stopped, the buzz returned, loud as ever. I tried using the switch on the power supply to run the hopper -- sure enough, the buzz went away again (and I could hear the alarm chime clearly). When I turned the motor off, the buzz returned loudly (with the alarm chime continuing until I reset the machine).

So... does that sound typical of the "Sammy squeal" -- that the buzzing would go away completely while the hopper is running? Thanks in advance.

[musky]

Just a general thought, may not apply to this case but, sometimes the buzzing is caused by the fluorescent lighting that introduces interference into the audio circuit.

[knagl]

Just a general thought, may not apply to this case but, sometimes the buzzing is caused by the fluorescent lighting that introduces interference into the audio circuit.

I had that thought, too -- I unplugged all of the lights, but the buzzing remained. :-/

Still curious if anyone can confirm or deny that the buzzing going away when the hopper is running is or is not typical of the "Sammy squeal."

[JohnD0406]

I have a Sammy, and it has a lot more background noise than other machines - it's even louder than the fan. I don't have volume controls on it yet, and expect it to go away with volume reduction.

What you're describing sounds like a ground loop. Perhaps some detailed pictures of the inside of your machine would help. I'm about to work on my machine, so I'll note grounding wires. I'm not too familiar with pachislos yet, but pachinkos have a ground wire connecting just about every component on the machine. I suspect pachislos are the same and you have one missing, dirty, or loose...

[autoslot]

I concur with Teqkng. Sounds like the power supply. I suggest buying another Sammy machine (you need more pachis anyway) and swap the power supply to see if that is it.

[JohnD0406]

I concur with Teqkng. Sounds like the power supply.

I somewhat concur as well, though any buzzing in the audio section will be due to a grounding issue, whether it be in the power supply or anywhere else in the machine. The fact that the buzzing goes away when the hopper activates validates that diagnosis.

Now that I think about it, it could be the hopper motor itself causing the problem. That'd be easy to diagnose by simply unplugging the hopper from the power supply. Does the buzz in the audio go away when the hopper is unplugged?

I suggest buying another Sammy machine (you need more pachis anyway) and swap the power supply to see if that is it.

That's great advice. You WILL need at least 2 or 3 machines, so this is a great excuse to justify buying more! Swapping parts is the fastest, cheapest, and most effective form of troubleshooting. Since you have a Sammy, may I suggest an Aladdin?

One last question. Is the wall plug 2-prong or 3-prong? If 3, get a "ground lift" from Radio Shack. They're those 2-to-3 prong adapters with a green wire sticking out, meant to add ground by connecting the wire to the screw on the wall plate. They're also very useful for disconnecting the ground for testing purposes.

[MrGoodBurn]

I had a similar problem with one of my machines as well. It turned out to be the transformer. It was a 100v transformer that was apparently installed in Japan. Stealth never changed it to a 110v transformer before they sold the machine to me. This can cause the power on the output side of the transformer to be higher than 24v. Some machines can handle the difference in power and some can't.

[rbinkerd]

I had a similar problem with a Welcome To Las Vegas Custom that was based on the George K. I added the small volume controllers to it and the buzzing is almost un-noticeable.

Rory

[knagl]

Now that I think about it, it could be the hopper motor itself causing the problem. That'd be easy to diagnose by simply unplugging the hopper from the power supply. Does the buzz in the audio go away when the hopper is unplugged?

One last question. Is the wall plug 2-prong or 3-prong?

I tried unplugging the hopper then powering it on -- the buzz remained. It is a two-prong plug.

I'm going to head to the local store tomorrow and see if they have any power supplies that would work. They for sure have pots (volume controls) there, so I'll pick up three of those and try that if I can't find a power supply. I'll also take and post some pictures of the inside of the machine as requested in a day or so.

[gvt1911]

I am new to this game also, but found that most transformers used today are not up to snuff for local higher line voltages...Here in NY I get 125-127 VAC and it kills my transformers in my vintage tube audio equipment...I had to install a varaic and lower the line voltage to 115 vac...Now everything runs quiet and cool...My Neo PlanetT says 100 VAC on the power supply...It works fine plugged into the 125 vac outlet, but gets HOT after 20 minutes...My question is should I install a Buck transformer and lower the line voltage down about 12 vac ? Maybe this could be your problem also ? Always best to have a variac in the house and see if buzzing is less at a lower voltage...

[knagl]

Well, I did eventually add the volume control pots that I bought. They clearly weren't the correct pots for the job as they went from full resistance (volume off) to no resistance (volume as full as before) with just 1/8 of a turn from the off position. Regardless, if I set them just right it partly eliminates the buzzing while the sound of the game can still be heard.

I've pretty much lost interest in the pachi, though. I own a few Vegas-style full size slot machines and prefer playing and tinkering on them. I haven't even plugged in the buzzer, er, pachi in months -- as such I'll mark this thread as "resolved" since that's the closest thing to "no longer a concern". Thanks to all for your help and troubleshooting steps.