Intellivision Power Switch

jmrank · May 7, 2010

With all the refurbishing of old systems going on in the world, I am literally shocked that I can't find an answer to this question...

I was messing around with my Intellivision today, trying to figure out which games worked and which didn't. Long story short, I flipped the On/Off switch to On, and something wasn't right. Turns out the power switch (under the fancy cover) had broken off.

No big deal, I figure... it's just a switch, right? Figure out what it is, go to Radio Shack, and replace it. Not so fast... tearing the unit apart just showed me that the switch has a lot more than two terminals underneath, and actually appears to be switching three different circuits (there are three pairs of wires hooked up to it).

Now, at this point, I don't know if it's three DISTINCT circuits, or just three sets of wires that eventually all hook together. Since I know there are a bunch of different types of current being used, I have to assume the three sets are distinct, and are just all being controlled by the single switch.

First of all, I can't seem to find a switch that can handle three separate circuits at once (maybe I'm not looking in the right place??). Second, I want to believe there is something out there that can handle whatever current the Intellivision is switching.

Given how easily the switch broke, I can't believe I'm the first to have seen this (nor the first to believe it can be fixed)... anybody else know where I can find a replacement switch to stick in there? I don't even care if it's the "same" switch; I just want one that works!

intvnut · May 17, 2010

With all the refurbishing of old systems going on in the world, I am literally shocked that I can't find an answer to this question...

I was messing around with my Intellivision today, trying to figure out which games worked and which didn't. Long story short, I flipped the On/Off switch to On, and something wasn't right. Turns out the power switch (under the fancy cover) had broken off.

No big deal, I figure... it's just a switch, right? Figure out what it is, go to Radio Shack, and replace it. Not so fast... tearing the unit apart just showed me that the switch has a lot more than two terminals underneath, and actually appears to be switching three different circuits (there are three pairs of wires hooked up to it).

Now, at this point, I don't know if it's three DISTINCT circuits, or just three sets of wires that eventually all hook together. Since I know there are a bunch of different types of current being used, I have to assume the three sets are distinct, and are just all being controlled by the single switch.

First of all, I can't seem to find a switch that can handle three separate circuits at once (maybe I'm not looking in the right place??). Second, I want to believe there is something out there that can handle whatever current the Intellivision is switching.

Given how easily the switch broke, I can't believe I'm the first to have seen this (nor the first to believe it can be fixed)... anybody else know where I can find a replacement switch to stick in there? I don't even care if it's the "same" switch; I just want one that works!

Schematic for that switch

It looks like the main transformer provides three lower voltages to the main power supply board, and that switch is switching all three together. Take a look a the link above so you can follow along. The main on/off switch is SW501, and that's the one that's kinda shown in the middle left part of the schematic in the bottom-left part of the page.

If you really, really want to simplify things, you could short out the corresponding wires (uh... Light green to dark green; Dark green to the other dark green; and blue to blue??? Who came up with this coloring!?!?) and then just use a switched outlet strip to turn the unit on/off. (Or, break the 120v before the transformer and install a switch on that.)

Alternately, you could look for a three-pole-single (or dual)-throw switch out there. It appears that Digikey stocks one that would be appropriate. (That's Digikey part number SW121-ND, just in case that link stops working.)

Otherwise, if you really want an official Mattel replacement switch, perhaps I could be talked into parting with one from my Intellivision graveyard. If you're interested in that, give me a holler at intvnut AT gmail dot com.

One further edit: You can download the entire Intellivision service manual scan here.

Edited May 17, 2010 by intvnut