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When I was a kid with a Nintendo Entertainment System (NES), sometimes my games wouldn’t load. But I, like all kids, knew the secret: take out the game cartridge, blow on the contacts, and put it back in. And it seemed to work. (When it failed, I’d just keep trying until it worked.) But looking back, did blowing into the cartridge really help? I’ve talked to the experts, reviewed a study on this very topic, and have the answer. But first, let’s talk tech.


The NES console marketed in the US looked very different from Nintendo’s original Famicom console sold in Japan. The Famicom (short for Family Computer) is shown above — it featured a top loading design in which you crammed the cartridge into a slot on the top. (It also featured a snazzy red-and-cream color scheme that to my eye looks a bit like Voltron.) By putting the cartridge in on top, the label on the Famicom cartridge served as a kind of billboard, advertising the game currently being played. When Nintendo created the NES for the US, a major design change was to place that cartridge slot deep inside a VCR-style gray box (shown below). It was similar technology, but hidden in a way that American consumers might assume was more like a familiar VCR — and more importantly, different from game consoles like the Atari 2600, which were old news. Nintendo wanted to be new, and better — so it hid its slot.

What Nintendo tried to emulate was a “Zero Insertion Force” (ZIF) connection — a phrase that sounds like a bad joke about problems in bed, but is a real engineering notion. A ZIFconnection is one in which the user doesn’t directly press the cartridge into its host connector — no insertion force is exerted by the user. This is a good thing from an engineering standpoint because users can do things like push too hard, and eventually connectors that require this kind of contact wear out. A typical mid-to-late 80s VCR is a variant of ZIF design: the tape goes in the front, then the machine grabs it and gently pulls it into place. That’s a pretty durable design. That’s not what the NES had, though. Its slot required insertion force, and it was buried inside a box — making it hard to fix when things went wrong.

In the NES, the user opened a front flap, slid a cartridge into the machine, and the insertion force occurred at the back of the machine, where the (hidden) cartridge slot lived — pins within the cartridge crammed up against the slot in the back. Then the user pushed the cartridge down (again emulating the behavior of a VCR) and powered on the console. This little ritual felt very satisfying, but over time the cartridge slot got dirty, its springs wore out, and the cartridges themselves got dirty. All of these factors worked together to cause poor contact between cartridge and slot, which meant your game just didn’t work — the machine couldn’t communicate with the cartridge over a bad connection, and frustration ensued.


Nintendo designed its NES connector using nickel pins bent into a position so that they’d give slightly when a cartridge was inserted, then spring back after it was removed. These pins became less springy after repeated use, which make it hard for them to firmly grasp the game cartridge’s connectors. To make things worse, the cartridges themselves had copper connectors. Copper tarnishes when exposed to air, causing it to develop a distinctive patina. While this patina was often not bad enough to cause problems, an overzealous kid (ahem, like me) might notice this effect and (ahem) attempt to remove it using all sorts of things from erasers to steel wool to solvents (side-note: my father, being a computer guy, had access to a magical substance called Cramolin — apparently worth its weight in gold, it could clean anything). Enough overzealous cleaning could ruin a connector, rendering the cartridge unplayable. I know this because I did it.


When things went wrong inside your NES, the problem was usually a bad connection between the cartridge and its slot. That could be due to tarnishing, corrosion, crud in various places, weak pins in the slot, or other issues. The symptoms of a bad connection could include the game not starting at all, the console showing a blinking light, or the game starting up with garbage all over the screen (below, a photo of Zelda II shows this form of startup glitch). To combat these problems, in the mid-1980s my friends and I somehow learned this secret: if we took out the cartridge, blew in it, and reinserted it, it worked. And if it didn’t work the first time, it eventually worked, on the second or fifth or tenth time. But looking back on it, I wondered: did that blowing actually help? And if it did…why? Was dust the culprit, and I was blowing it out of the cartridge? I spoke with several experts (who insisted they were not experts, despite their backgrounds) to find out.

First up, Vince Clemente, producer of Ecstasy of Order: The Tetris Masters — a documentary about players of the classic NES Tetris. Clemente said, “[Blowing in the cartridge] is actually terrible for the games and makes the contacts rust. You’re really not supposed to do it. But it works. [laughs]” This sums up the problem: although intellectually we knew that blowing into electronics was bad, we did it anyway. It seemed to work.

So I turned to another authority, Frankie Viturello, who is one of the hosts of the gaming show¬†Digital Press Webcast among many other gaming-related projects — he also worked in a game store for years. Viturello’s first response was: “While I admittedly may have dabbled in a little cartridge-blowing as a naive NES-playing youth, I’ve long-since been an advocate for not doing it with the stance that for whatever it may do to aid in the temporary functionality of an NES, it ultimately opens the door for damage and distress to the hardware.” So I went deeper — in the following mini-interview, I have added emphasis in various places.

According to Viturello-

“The theory that ‘dust’ could be a legitimate inhibitor and that ‘blowing it out’ was the solution, still sounds silly to me when I say it out loud.”

So, WHY does blowing into a cartridge have any effect?

“The most reasonable explanations — in my opinion — are: 1.) The act of removing, blowing in, and re-seating a cartridge most likely creates another random opportunity for the connection to be better made. So removing the cartridge 10 times and putting back in without blowing on it might net the exact same results as blowing on it between each time. And 2.) The moisture that occurs when you blow into a cartridge has some type of immediate effect on the electrical connection that occurs.”¬†

Hence Viturello emphasizes that blowing in the cassette only ruins it more than it helps.


In a brief note on its NES Game Pak Troubleshooting page, Nintendo states:

Do not blow into your Game Paks or systems. The moisture in your breath can corrode and contaminate the pin connectors.


So, dear readers, all signs point to no: blowing in the cartridge did not help. My money is on the blowing thing being a pure placebo, offering the user just another chance at getting a good connection. The problems with Nintendo’s connector system are well-documented, and most of them are mechanical — they just wore out faster than expected.

Having said that, it’s true that kids can be grubby, and getting crud into the cartridge or slot was a real problem — I suspect that most of that crud was not just dust, though, and required a more thorough cleaning than a moist mouth-blast could provide. In fact, Nintendo released an official NES Cleaning Kit in 1989 in an attempt to keep both the slot and cartridges clean. Ultimately, Nintendo redesigned the NES console, releasing an NES 2 console in 1993 that’s commonly known as the “top loader.” Its main feature? A top loading slot. It was more like the original Famicom, using a slot that held up better to abuse. Similarly, the SNES (Super Nintendo Entertainment System) was a top loader.

And when I asked Viturello about cleaning cartridges, he told me:

“The best methods for cleaning game cartridges are: isopropyl alcohol and swabs or, more recently I and others have discovered that non-conductive metal polish such asSheila Shine or Brasso is very effective and also helps to protect against some of the elements that would otherwise cause that natural tarnish that occurs through regular exposure to the elements and standard usage.”