How to Find a Cheap, Brand Name Intellivision 2 Power Supply

Intellivision 2 power jack and Microsurgeon game screen

I was very excited when I got a great deal on an Intellivision 2 console. But like most of these, mine came without a power supply. Original power supplies are not always easy to come by, and I’m wary of off-brand units that could have quality and safety issues. So what’s a good substitute?

How can I replace a missing Intellivision 2 AC adapter? I went looking for a quality replacement for my Intellivision 2’s power supply, and I learned how to get a brand name solution for $8 - $14, instead of the off-brand eBay stuff costing $25 - $30.

Table of Contents

Ataris and Nintendos are everywhere, but the Intellivision is a much rarer bird. I had one as a kid, and loved it. I got used to seeing them these days in retro game stores looking a little rough, and carrying price tags of eighty dollars and more. So I was completely stoked to come across a pristine Intellivision 2 unit, and get it for an unheard-of fifteen dollars. The only catch was that I couldn’t get straight to gaming, because it had no power supply.

My Intellivision 2
My Intellivision 2 came to me in great shape, but missing a power supply

As I started googling, I found plenty of forum discussions about the fact that most people who buy these get them without a power supply (AC adapter). I also saw that a lot of people had run into frustration finding a proper replacement, and those who had found make-do solutions were having to spend some non-trivial coin to get them - like Atari 5200 power supplies sometimes running $25-$30 or more. I’m no cheapskate (I believe in spending money where it’s needed), but I am frugal. If I can get quality for less, why wouldn’t I?

What Kind of Power Does the Intellivision 2 Need?

Understanding how to do this required getting schooled by my betters in an online discussion forum for console modding and repair (and some double-checks with IRL friends who also have electronics knowledge). I won’t make you learn all I did, but I do include it down at the bottom because it’s very helpful to know, and if you want to replace power on other consoles, this same approach can save you some dollars while getting you better gear. Who doesn’t like that?

Know your power spec. The Intellivision 2 (or more correctly, the Intellivision II) was Mattel’s updated, streamlined version of the original Intellivision. They brought it out in 1982, and it’s not a next-gen, like the Playstation 2 is to the Playstation, but really just an updating like the Playstation 2 Slim is to the original Playstation 2. As a part of this update, the power supply was changed, so Intellivision 2s have their own special doohickie (which is why so many have been frustrated in looking for them).

The specs for the Intellivision 2 power supply came in two versions:

  • 16.7V - 1.0A
  • 16.2V - 955mA

The original adapter outputs AC (alternating current), but the console will also take DC

The original Intellivision 2 AC adapters

16.7 and 16.2 are pretty oddball voltages, but the console is tolerant of some variation. It doesn’t have to be EXACTLY these specs. Many who are using an Atari 5200 power supply say their Intellivision 2 has worked well for years on it, even though the Atari supply only puts out 9 volts. Some speculate that the console needs less overall voltage when running without fancy add-ons, like the Intellivoice speech synthesizer. This acceptance of much lower voltage is a bit odd, and not how most consoles work.

Get a High-Quality, Brand Name Power Supply for That Intellivision 2 (for Less!)

When finding your power supply, watch for 3 key things:

1) You want a power supply that outputs the much more common (but very close) 16 volts, and 1 or more amps in DC (direct current). The answer - the laptop power supply.

You can confirm the output from the adapter you’re looking at by looking on the label to find where it shows the breakout:

Two 16V power supplies with highlighted labels showing output and polarity
The output from both of these laptop power supplies is 16V DC. We know it’s DC for two reasons: the line over 3 dots between the voltage and amperage (AC shows a ~), and the polarity indicator (AC output has no polarity). We also know from the polarity indicator that both of these are center-positive. Finally, the left unit (which I purchased) has output of 4.5 amps, and the right unit has 4 amps - both meet and exceed our 1.0 amp requirement - which is fine, on amperage (see below).
  • 16V - 1.0A+

It’s also important to note here that we’re looking for DC output, not AC. The original Intellivision 2 power supply actually output AC current, but the console is perfectly happy receiving DC current as well. When you look at the output on the labels above, note that the output has two things indicating that it’s DC:

  • It shows the line & dots symbol between the volts and amps
  • It has a polarity indicator symbol - see below at #3 (AC output has no polarity)

2) Make sure the end that plugs into the console is a 2.5mm X 5.5mm barrel connector. This means the connector is round, with a round hole in the middle. The measurement reflects:

  • 2.5mm inner diameter (for the pin in the center of the jack on the console)
  • 5.5mm outer diameter (for the size of the outer hole)
2.5mm X 5.5mm barrel connector, and Intellivision 2 power jack
Barrel connectors vary some in appearance, but are always cylindrical, with a hole in the middle. Pictured right, the jack on the Intellivision 2 that takes the 2.5mm X 5.5mm tip (barrel connector).

3) Make sure that the connector is center-positive (most are). This means that the inner part of the barrel carries the positive pole for the DC current output, and the outer part carries the negative. You can tell this quickly by looking at the label, and finding the polarity indicator mark:

Polarity indicators - center-positive, and center-negative
The two symbols look identical at a glance. The key is to look at which pole is connected to the center dot. The exact style of the symbols may vary (such as the diamond shapes in the previously shown photos), but the concept is always the same. 

Make sure the label shows that it’s center-positive. See the previously shown highlighted label photos for examples.

eBay a Brand Name Used Laptop Power Supply, Not Overpriced Jankiness

16V is a common voltage for laptop power supplies. I have seen plenty from Toshiba, Lenovo, etc. When you buy that kind of quality, you don’t need to have the sort of concerns about failure or safety like with the (higher priced) off-brand-from-China stuff. Do an eBay search like:

“used 16v laptop adapter”

(and don’t forget to set the list order to “Price + Shipping: lowest first” like I did in the link above)

Be sure you are getting an original item from a manufacturer like IBM, and not a third party replacement listed as “for IBM,” etc.

The best way to double check the sizes on the barrel connector is to grab the product/part # of the item, and google it to get specs, like:

“ibm ac adapter 12J1441 mm”

This finds the part, and highlights where the measurement (in mm) is listed. Your search results are likely to show third party replacements, but that’s fine - we’re just looking to confirm the connector size. Be sure it’s 2.5mm X 5.5mm.

Make sure that the adapter you’re buying comes with the AC cable to plug into the wall. Not all of them do. If it’s not pictured, it’s not included. You might have something you could use in its place, but MAKE SURE you know the connector THAT uses, since some are kind of funky.

Alternatively, my local Goodwill has a computer section, and a box of miscellaneous power supplies. Time to do some crate digging.

In my looking, I was seeing lots of options, with many in the $8 - $14 range. You can’t beat that for something from a major brand. It’s much better than the sketchy options from off-brand companies that charge 2X - 4X the price.

Make Sure the Console Jack is in Good Shape

Check the console jack’s condition. It’s not uncommon for the metal connections in the jack to have a little surface rust. This can cause a failure to power up, or intermittent power. The solution is easy. Just roll up a piece of fine sandpaper (I used 400 grit) so that you make a small tube like a straw. The grit should be on the outside. The tube just needs to be long enough to go in the hole and still let you grip it. Insert, let it expand by uncoiling a little, then twist and push/pull to knock off surface rust. Re-roll it with the grit on the inside, and finesse the center pin a little, too.

The Geeky Bits About Power Supplies

There is a lot of misinformation on the interwebs about stuff like this. Misunderstandings and superstition get repeated like they are gospel truth. Learn these geeky bits, and you can cut through the confusion.

IMPORTANT: Every device has its own requirements, and while the Intellivision 2 is not super picky, other consoles may be. Ask, and know exact needs if you are looking to power something else.

AC and DC are different types of current. Alternating Current is what comes out of a wall outlet. The flow continually switches directions, and items set up to use DC, are likely to be damaged by AC. Direct Current flows in a single direction, and has polarity (as explained above). DC is commonly used in lower voltages, and typically comes out of batteries, and adapters that convert alternating wall current into direct current.

Make sure you understand the difference between input and output. For a unit that plugs into the wall in the U.S., the input will always be standard wall current. It will give a voltage range, an AC indicator, and a Hz (number of cycles per second), which is 60 (sometimes given as a range of 50-60). It will also show the amount of current (amps) it pulls.

Output is marked in DC or AC (line + 3 dots symbol for DC, or squiggle line for AC) between the volts and amps. This is what comes out the barrel connector into the console you plug it into.

Having a voltage that’s too low will not damage your components. Having one that’s too high, may. I saw concerns over low voltage causing damage to consoles a number of times. They had no explanation why, but stated it emphatically, with superstitious certainty. In reality, if the voltage is too low, the thing just won’t work, or won’t work properly. It won’t be harmed. If it’s too high though, you could overheat, or blow something. Don’t go over on voltage.

Meet or exceed the amperage your console wants. Amperage ratings show the amount of power a supply CAN send, not the amount it WILL send. If you need 1 amp, and the supply states 3.5, then you just have unused capacity. On the other hand, if your power supply tops out at less than the console needs, the supply could overheat, or catch fire. Don’t do that.

Don’t use reverse polarity, or you can damage things. The Intellivision 2 wants a center-positive configuration on the barrel connector. The center should be the positive pole, the outer is negative. Make sure your power supply is set up this way (the symbols look identical, just reversed). Using the wrong polarity could cause damage.

The internal rectifier in the Intellivision 2 will let you just feed in DC current, even though it expects AC. The Intellivision 2’s internal rectifier is designed to receive AC (alternating current) input and convert that (rectify it) to DC (direct current). If you save it the work, it’s fine with that.