Fix a Vintage Simon Game




Introduction: Fix a Vintage Simon Game

About: Indie Film! Art science! Reuse and sustainability!

I recently got a new "Simon" game! They re-made it! Huzzah!

But when I played it, something was... lacking. It wasn't how I remembered it from the 1980s.

The buttons on this new one didn't move. The game didn't have the heft of the old ones. The tones sounded different. Even the lights weren't the same.

I realized the new one was built to be a lot cheaper. So I went on eBay and got a vintage "Simon."

Not only is the vintage "Simon" better from a aesthetic perspective, it is also boasts superior engineering, albeit with 1970s technology. It is fixable with a screwdriver and is thus more sustainable.

So how do you get a sick "Simon" back into fighting shape?

You will need:

  • fresh batteries
  • a Phillips screwdriver
  • some way to test circuit continuity - I'm using a multimeter

Step 1: Check Your Batteries

The only disadvantage of the 1970s "Simon" is it is a bit of a power hog.

It requires a 9V battery, AND two "D" batteries. Why?

  • the 9V battery powers the chip logic, the "brain." Back then it was referred to as a "transistor battery," to distiguish it from...
  • the two "D" batteries, which primarily power the incandescent light bulbs under the buttons


  • check all three of your batteries and make sure they are fully charged
  • bonus points for rechargeable batteries!
  • The light bulbs use a lot of current though, so putting rechargeable "AA" batteries in a "D" form may not be great.

Step 2: Open Up Simon

Now that we know the batteries are not the problem, let's look under the hood.

  • flip Simon over so the colored buttons are faced down
  • Unscrew the four Philips head screws on the bottom. Put the screws in safe place.
  • gently lift off the entire bottom of the game!
  • you will note the tops of the switches come off and lie there! This is normal. Make sure you don't lose them!

Now you have

  • the bottom half, which has all the stuff that does anything
    • the light bulbs
    • the contacts for the buttons
    • the switches
    • the chips!
  • and the upper half, which I'll call the "lid," which is all just plastic fronts for the functional parts
    • the 4 colored buttons for the game
    • switch covers
    • the 3 colored buttons for starting a new game or reviewing the last one. Be careful, they fall out easily!

Step 3: More Simon Anatomy: the Bottom

  • There's a paper ring on the edge of the board.
  • This board has
    • four light bulbs on it!
    • all the switches for the game, implemented as little clicky strips of metal
    • the three sliding selector switches
    • a chip which holds all the program for the game
    • a smaller chip which is the power control for the light bulbs
  • The board is held onto the bottom half of the cover with four more screws, and the wires running to the 9V battery and speaker

Step 4: How To: Fix Stuck Buttons

With your finger, click every little metal rectangle.

When you press it, it's connecting the metal to a contact underneath it. This is as simple a switch as you can get: no springs, nothing.

If you don't feel a click, the button is broken!

The way you fix it: bend the metal so it's not usually touching the contact, until pressed. That's it!

Step 5: How To: Fix Stuck Game Buttons

If one of the big four buttons doesn't seem to be pressable, here's what may be your problem:

  • between each two buttons is a plastic "X" held in by a single screw
  • this plastic X has two functions
    • hold the button in place
    • act as a simple spring
  • it may happen that one of the arms of the X is broken, or in the wrong place
    • if in the wrong place (as pictured), just unscrew it, replace it, and screw it back together
    • if broken, you can put a new spring in here

Step 6: How To: Fix Non-lighting Buttons

You may here the game sounds, but the buttons don't light up

  • if only a single button is not lighting, the problem may be a burnt-out bulb
    • these are standard bulbs you can find at a hardware store
    • BUT also - Milton Bradley engineers included an extra bulb inside Simon! Thanks, guys! If you think engineers still do that, you haven't taken apart many toys recently!
  • if ALL the buttons do not light,
    • your "D" batteries may be dead
    • the contact from the "D" batteries may need to be cleaned (see below page)
    • the power chip may be dead
      • this would be a bummer, but it is not fatal - you can still get this chip. Buy a new one from Digi-Key or something and put it in!

Step 7: Detach Board

Further fixes require we get under the board! If you haven't already, unscrew the board and put the screws in a safe place.

Step 8: Check Power Connections

IF you are looking for wires connecting the "D" batteries to the board, you will be looking a long time!

In its normal working state, Simon's board sits directly on the contacts for the "D" batteries, and is held there by a screw running through the board into the contact!

As you can see, there is quite a bit of corrosion on my power terminals - the dreaded green crust.

Even though it looks like candy, DO NOT TOUCH THE GREEN CRUST. It is POISONOUS and also acidic. So how do we get it off?

Step 9: How To: Clean Battery Terminals

You can get this crust of in a number of ways:

  • sandpaper!
  • a dremel with... sandpaper!
  • or you can start with a Q-tip and some baking soda

The idea here is you make a sodium bicarbonate slurry with water, and you brush it on to weaken the acidic paste and neutralize anything dangerous before it touches your skin. I usually start with this step and then move into sandpaper.

NOTE that on Simon, once again the engineers have smiled upon us: the entire terminal can be easily removed for cleaning. I realized this after I started. Oops!

Step 10: Reassemble and Test!

Put Simon back together and play a few games.

  • do all the buttons work?
  • can you hear the sounds?
  • do the buttons light up?
  • does Simon play the victory sound?

Good luck!

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    Question 4 years ago on Step 6

    Only two of my lights no longer work. Sound is fine on all. I replaced all of the bulbs, no change. My husband says one ofthe transistors has gone bad. Can this be repaired? BTW, it's the green and red that no longer light.


    Answer 20 days ago

    The bulb driver is the SN75494N chip. It'd be worth checking all the traces from the bulb holders back to that chip to make sure none have gone bad.


    Answer 1 year ago

    Switches to the relevant bulb may need cleaning, due to age. (Those small metal strips, that you usually press when repeating the light sequence)


    Question 3 years ago on Step 5

    Hi, I've finally got around to fixing my old Simon and can't believe how great these instructions are! I have the same issue as Stewmack below - one of my 'X' spring arms has broken off. You mention in the article you can add a spring instead - have you got any suggestions around how to do this? I'm stumped. Thanks!


    Answer 1 year ago

    Gimme a shout, sure i've got a couple in a drawer, you can have one. orcada3 at yahoo dot co dot uk


    3 years ago

    So I have just taken apart and fixed my Simon game with the great help of these amazing instructions. I found my battery terminal (as batteries had been left in for years) were a little rusty and a little corroded. I took a bit of sandpaper to it then cleaned them up, down to the shiny silver metal and this was the main problem for me. Everything then started working with new batteries (after using the replacement bulb). The only thing now is one of the X spring arms for optimum button pressing have snapped so if anyone knows anywhere to get these I would love to know. Again thanks for these helpful instruction. Simon round the Christmas table for me this year


    Reply 1 year ago

    Gimme a shout, sure i've got a couple in a drawer, you can have one. orcada3 at yahoo dot co dot uk


    Question 3 years ago

    I'm wanting to know how to test the micro chips to verify function?With all cleaned with good lights and strong batteries,when I turn it on set to 1 on both levels and push start nothing happens for 45 seconds then the green bulb lights once with sound.It cannot be answered by pushing the green lens,but every 45 seconds it lights and beeps once on that cycle over and over??


    Answer 1 year ago

    Might be a daft answer, but have you checked all the flat metal switches to make sure they're not contacting constantly. Especially the green one.


    2 years ago on Step 3

    My son decided that the game didn’t work and took it upon himself to take it apart. Trying to put it back together. Where is the red wire connecting? Tried looking to see in the pictures and can’t tell what it should be connected to. My husband has to get a new 9 volt connection since my son cut the wire.


    Reply 1 year ago

    Hi-ya, the red wire from the 9volt battery goes to the right hand leg of the on off switch when viewed from the top front of the board. It's also to the left of the black wire when viewed from below. (You should see two small holes, one with the black wire going in.


    2 years ago

    Hi friend! Very nice Topic!!!
    Please. Help me!!! I need to buy the skill switch, the Game switch and the power switch!!! I can´t find it anywere!!! Can you please read a number or model or anything on your switches to help me on identifying its??? Thanks friend!!!

    Directions were great! Mine is a 1978 vintage. It’s amazing how much power those bulbs consume. It turns out my main problem was 1 of the 2 D cells was dead. However, I just thought it was my kids destroying a 42 year old game...whew!


    6 years ago

    I'm right there with you! I bought a a vintage Simon on eBay for the same reasons. Man it's fun.