The Problem
This is a demonstration of a technique to install LED lights to your Twilight Zone clock board instead of 4 #86 lights that came with the game. Why? Because #86 lightbulbs (along with resistors) emanate a lot of heat inside the clock housing, and the heat is literally trapped inside the clock having no vents to get outside. There are 2 small holes on the bottom of the clock housing meant for 2 connectors, but that is not sufficient. According to some accounts it gets up to 160F degrees inside the clock. The result is 8 optos and the boards get fried and cooked inside, resulting in a very common message on many Twilight Zones "Clock is broken", or malfunctioning optos and all kinds of other problems. This technique will attempt to show how to remove the #86 light bulbs and use LED lights that do not get overheated thus reducing the temperature inside the clock housing.

The Solution
This technique is demonstrated on a 1993 Bally™ Twilight Zone pinball machine. If you are not confident in your repair abilities and if you have never done this before, I do NOT RECOMMEND doing this fix. If you would still like this mod done to your Twilight Zone clock, but you cannot/do not want to do it yourself, I will gladly do the mod for you for free. All you need to pay is shipping charges for your clock board to Houston, Texas and materials needed (4 LEDs and 4 resistors). Feel free to email me anytime if you need any help with this.

There are several solutions to this problem. Some people drill holes on the top of clock housing that lets the heat escape outside. I am not a big fan of that. Another trick is to replace #86 bulbs with slightly dimmer ones thus reducing the heat again, but not by a whole lot.

Third way is to buy a Pinball Lizard board, which is a complete replacement for your clock boards. This is the easiest solution, but these boards are sort of pricey, although heartily recommended by many in the pinball community. I have never tried those boards, so I cannot comment on that.

And the last technique is to use LED lights modification. This is what we are showing below. I did not "invent" this technique or thismod, it has been done before. Joel from "Pinball Lizard", I believe, was the first. I am much indebted to him, and also to Clay Harrel, owner of great pinball repair guides and his "This Old Pinball" tapes where he shows this mod while we follow him fixing everything on his Twilight Zone machine.

You will need 4 white 5 mm LEDs and 4 100 Ohm 1/4 watt resistors. These parts should be available in any electronics parts store, and Radio Shack® also carries them. You then unsolder #86 bulbs and solder LEDs in their places. You will need to solder your new resistors on locations D1, D2, D3 and D4 as shown in detailed pictures below.

IMPORTANT! Please use due care and precaution while attempting to do this mod. Use at your own risk. If you don't have any repair or refurbishing experience, if you don't have any soldering/unsoldering experience, if you don't have proper equipment to perform these tasks and/or knowledge, please do not work on this board, and please DO NOT attempt to do this mod. I will do it for you for free, if you wish to prolong the life of yoru Twilight Zone clock.

This webpage is for informational purposes only. I will not be held liable or responsible for any damage that occurs to your pinball machine or any bodily injury or any kind of damage by use or misuse of this technique.