Data East Simpsons Pinball

Repairs, Restorations, Tweaks and Insights


Data East Simpsons is another pinball machine that my wife and I played in college.  I looked for a decent one for several years.  They show up periodically, but they are often trashed!  It's either the playfield, the cabinet or both that are in poor shape.  I was very happy when one became available locally that was in pretty good shape.  It certainly needed a good shop job and the playfield had been touched up in a few places, but it looked like it would clean up nicely.  It was by far the nicest one I had seen.  All in all, DE Simpsons is not a super complex game.  It's the integration of the theme that makes this a worthy addition to a pinball collection.

What's cool about Simpsons?

Here are some interesting aspects of Simpsons

  1. Playfield artwork is really fun to look at.  Tons of stuff to see.

  2. The Simpsons music is integrated into the game perfectly

  3. It has a cool Bart Simpson topper

  4. Rather than regular bumper caps, this machine has nuclear power plant bumper caps!  Way cool.

  5. Two vertical up kickers

  6. Two separate ball locks, one on each side of the playfield

  7. Eight (count 'em) drop targets!  Three in the center of the playfield and 5 more on the right of the playfield.

Backbox GI Problem

Original 2/3/2012

Around May of 2012 my DE Simpsons blew a fuse for the backbox GI. If I recall, a bulb went bad and shorted. I replaced the fuse, only to find that it blew again shortly. I replaced it once again, thinking I'd be lucky and find it was just a bad fuse (knowing it was unlikely), but it blew again. For the next 8 or so months this issue was on my list to look into, but I couldn't dig up the energy to look into it.   I finally spend a few hours and looked into it.

I started by replacing the fuse again (F2 on the PPB) and trying to reproduce the problem.   It took a good 45 minutes, but it happened again.   I managed to take a picture of the bright/glowing fuse right before it burnt up.   See the picture below.   F2 is the bright fuse second from the bottom.

There are 2 GI circuits for the backbox, F2 and F4. I was only replacing F2 since I didn't realize F4 was also bad. But something strange occurred when only replacing F2.   All of the GI lights, not just the GI string associated with F2, worked!  How could this be?

It turns out a previous owner had done some hack and connected the hot from GI string 1 to the hot on GI string 2. I should have noticed the strange black wire between the GI strings earlier. Among other things, this meant that all GI would run from only a single circuit if either of the GI fuses blew.

There are around 30 #44 bulbs in the backbox. That's too many for just a single 5 amp fuse. #44 are rated at 0.25 amps... That is 7.5 amps. This is fine for two 5 amp circuits (as designed) but not for one 5 amp circuit.

Since I didn't realize both fuses were bad, when I only replaced F2 all the current would run though F2 instead of F2 and F4.   F2 would "do its job" and blowing.   Once I replaced both fuses, everything worked fine.

I removed the hack jumper between the two circuits since it shouldn't be there. Who knows why it was added in the first place. It's certainly not good to have if one of the fuses blows.

Alpha-Numeric score display started acting funny

I was playing Simpsons and looked at the alpha-numeric display at the end of the game.  It was fading in and out, different segments at different times.  When the game went into attract mode, I kept watching the alpha-numeric display.  It would look fine occasionally and then it would fade out.  I immediately though the display was out-gassing, but then quickly though that it wouldn't go from working fine to such a big problem in a short period of time.  I started looking elsewhere.

The display board uses +100V and -100V.  Using my DMM I could see that when the problem occurred, the voltage would be around +/-50V.  It strongly appeared to be a power supply problem.  Using the invaluable resource at, I quickly found that 2 resistors are known to cause problems for Data East display power.  These resistors are R8 and R9 (39k Ohm 1 Watt).  The site also mentioned that diodes D6 and D8 (1N5228) can also be common trouble makers. 

It didn't make sense to take the board out, only replace the resistors, put it back together and test.  I replaced all 4 parts (2 resistors, 2 diodes) when the board was removed.  Problem solved.  Display looks great.  I even left it running for several hours just to be sure.

I tested the removed parts and they tested fine.  Clearly, however, at least one of them was failing under the stress of heat.  So I don't know if the resistors were going bad, the diodes were going bad, or both ... but I know replacing all of them fixed the problem.

Update 12/13/09: The problem came back!  Since I had just replaced the typical problematic parts, I reflowed most of the solder connections for the cables.  It has been about 2 weeks now and the problem has not come back.  Keeping fingers crossed...

How did you replace the drop target decals?

The two leftmost bowling pins were clearly a poor reproduction.  The left picture below shows the original drop targets and the right picture shows the restored drop targets.  In addition to new decals, I replaced the plastic drop targets.

two leftmost bowling pins were clearly a poor reproduction.  The left picture below shows the original drop targets and the right picture shows the restored drop targets.  In addition to new decals, I replaced the plastic drop targets.

Replacing the drop targets is very easy.  Here are the steps.  A picture of the 3 drop target mechanism follows.

  1. Loosen the two hex nuts on the back side of the drop target mechanism.  This allows the drop targets to be removed from the drop target mechanism.

  2. Disconnect the spring from the drop target.  Each drop target has a curved piece of plastic that the string attaches to.  Simply push the spring toward the target and move it around the curved plastic.

  3. Pull the drop target up through the top of the playfield.  It comes right out.

What does the inside of a Data East backbox look like?

I had never seen this myself so I took some pictures to share.  The first image below shows the PCBs behind the backglass.  This is followed by a picture of the front of the door behind the backglass and the backside of the door.  Finally, there is a picture of the alphanumeric display board.

Anything interesting about the inside of the cabinet?

It appears the Data East uses a simple cardboard tube to increase bass response.  My (very) informal analysis showed that this tube does indeed improve bass response.  A picture of this bass-tube is shown below.  If you look down into the tube, you can see there is an opening.

How about pictures of the playfield with the ramps removed?

Here are some pictures of the back of the playfield.  This first picture shows the back of the playfield.

In the following picture you can see a previous owner used blank paint to repair the playfield.  While this repair isn't obvious when the game is put together, you can see the previous owner didn't repair Moe's shoulder.  Instead, black paint was used over his shoulder.

This second image shows another small repair done by a previous owner.  The waterfall just below the spinning target is half missing.

Any pictures of the big ramp?

Yes! But these really don't do justice to the size of this ramp.  It is really huge.  It's the largest pinball ramp I've seen.  The entrance to the ramp has a hidden plastic piece shows a Behemoth RV (I think).

In order to remove the big ramp, the smaller green wireframe must also be removed.  Below is a picture of the green wireframe.

How does the Millions plastic on the back of the playfield work?

It's individual piece of plastic that attaches with 4 screws.  The first two pictures below show the front and back of this piece.  The third picture shows what the playfield looks like when this piece is removed.  Finally the fourth picture shows the assembled Millions piece.

Is there anything fun on the apron?

Not surprisingly, yes!  Homer and Bart are happily providing the player with some useful information.

Want to see some pictures?

I'm just getting started.  Here are some pictures.

Doughnut Lanes with Homer

Nuclear Power Bumpers

Yellow Wire Ramp with Homer, Marge, Lisa, Maggie and Bart

Homer, Marge, Lisa, Maggie and Bart

Bart with Slingshot and Flippers

Backglass and Toppe (Bart, Homer, Lisa, Marge)

Bart Simpsons Topper

Anything interesting about the backglass?

Yes there is!  It's the only pinball machine that I own that actually has a backglass!  I'm specifically not using the term translite.  A translite is a plastic-like substance that has the image printed on it.  A translite is placed behind a separate piece of glass to give the traditional backglass look.  Data East Simpsons has the artwork printed directly on the glass.  Another cool aspect of this backglass is that it is mirrored.  Many of the Simpsons characters are outlined with a reflective surface.  Finally, it's a large backglass compared to Williams translites.  This is because the backglass includes the area that a 1990 Williams machine would use for the dot matrix display.

You may have noticed that the Simpsons backglass image on my home page is the same size as the other Williams translites.  This is because I cropped the image to be the same size.  It looked awkward being the only image that was a different aspect ratio.  For your enjoyment, below is an image of the Simpsons backglass.  Some parts, such as the Data East logo did not photograph well... I blame this on the mirrored backglass!

Which Simpsons characters appear on the backglass?

I'm no Simpsons expert, but I've managed to identify the following characters from the backglass: Bart, Homer, Marge, Lisa, Maggie, Krusty the Clown, Slideshow Bob, Moe, Barney, Milhouse, Edna Krabappel, Mr. Burns, Waylon Burns, Apu, Grandpa, Patty & Selma Bouvier, Santa's Little Helper, Snowball II, Otto, Bleeding Gums Murthy, Sherri and Terri.

How does the backglass look in the dark?

Pretty sweet.  See for yourself...

How about the bottom of the playfield?

Sure! Here is a picture showing the bottom of the Simpsons playfield.