I found these old pics from my ancient Geocities page - so they return again.....:

Xenon is a really fun game that has a clear "Tube Shot" that is lit by little 6v bulbs.

Because these bulbs have hair thin leads, they are always broken or just burned out.

A few years ago I was repairing a Xenon that had 1/2 the bulbs out and did not have any of those tiny bulbs in my box; but I did have plenty of LEDs. I figured that the LEDs would probably never burn out, and could be a cool blue color to match the blue pop bumpers.

LAMP-BOARD.jpg

Often it is helpful to refer to a schematic before making any modifications.

Looking at the Schematic, we can see that there are 10 bulbs, in 5 pairs, all driven by a single common buss line.

So at any one time we have 2 bulbs lit up.

The bulbs are in 5 circuits parallel to each other.

The circuit is powered by 6 volts, but my Blue LEDs want 3.3V, so we need a current limiting resistor.

SCHEM.jpg

So we will need to cut the buss line.

CUT-BUSS.jpg

And install our current limiting resistor.

INSTALL-RESISTOR.jpg

Now that we have our circuit mapped out, we can start modifying the actual board.

First, remove all the old bulbs, then install the LEDs.

Leave enough LED leg above the circuit board so you can bend the LEDs sideways after installation.

LEDs have polarity, so the flat side of the LEDs will all need to face the 7 pin connector (if you can't see the flat side of the LED, it's the shorter of the two legs).

Here we cut the buss line trace with a razor knife:

CUT-TRACE.jpg

Solder one leg of the resistor to pin 5 of the seven pin connector.

SOLDER-RESISTOR.jpg

Here we complete the circuit trace we cut with the other end of the resistor.

For safety, we cover the resistor with heat shrink tubing to prevent a short circuit should an air ball crash into it.

COMPLETE.jpg

Here we test our LED populated board before screwing it all back together.

Because LEDs have much more light emitting from the top than the sides, remember to bend the LED bodies so the tops are facing the tube itself for maximum effect.

TEST-RUN.jpg

So that's it.

With less than 5 minutes work and .51 cents in parts, you have hopefully replaced the last tube bulbs in your Xenon ever, and you have dressed it up with a cool color.

Remember, you don't have to use blue LEDs, Red would also be a great color choice to compliment a Xenon.

Also if you ever wanted it back to stock, just snip out the resistor, solder over the cut trace and reinstall your bulbs.

I got a couple of emails asking what resistor I used.

It looks like I used 82 ohms for that job, but that does not mean your LEDs will use the same resistor.

Different color or brightness LEDs need different resistors.

And since a lot of you guys want a turnkey solution and not a lot of electrical theory, we will use this as a "just make it" example.

This blue LED:

http://www.taydaelectronics.com/leds/round-leds/5mm-leds/blue/led-5mm-blue-water-clear-ultra-bright.html

Will need this Resistor:

http://www.taydaelectronics.com/resistors/1-4w-carbon-film-resistors/10-x-resistor-82-ohm-1-4w-5-carbon-film-pkg-of-10.html

http://www.quickar.com/noqbestledcalc.htm

This calculator will let you plug in the specs for any LED (for those who don't like math).

This Red LED:

http://www.taydaelectronics.com/leds/round-leds/5mm-leds/red/led-5mm-red-water-clear-ultra-bright.html

Will need this resistor:

http://www.taydaelectronics.com/resistors/1-4w-carbon-film-resistors/10-x-resistor-100-ohm-1-4w-5-carbon-film-pkg-of-10.html

Flat side ( AKA the Cathode, negative, or short lead) needs to face the 7 pin connector.

Cathode-side.jpg

(sorry I was not more clear about this before.....old pics and old descriptions...that's my excuse )

Get a piece of "surface wiring trak" from the hardware store and make something like thierryv excellent example above.

Then follow the yellow schematic above and wire it by hand.

There are a couple of very easy solutions to use LEDs in Classic Bally:

https://pinside.com/pinball/forum/topic/classic-ballystern-led-adapter-kit-review