DIY Computer Cathode Light Project

Photos and writeup by Trevor Freeman. September 2008.

Dell Dimension desktop with green fluorescent lights installed. While it was never a top performer even in its day, I have become very fond of our little Dell Dimension 4100 desktop computer. In the eight years we have had it, the computer has proven itself to be a stable and reliable workhorse of a machine. Over the years the computer has received a number of upgrades including a DVD/CD burner, more memory, a larger hard drive, an air intake fan, and a custom case window; yet the core components of the system are still going strong.

It still has the original 150-watt power supply. It has the original 800MHz Pentium 3 processor, which gets by with a fanless heatsink. The motherboard has only two slots for memory and it is maxed out at 512MB of PC133 SDRAM. Since it is no longer my primary machine, the old computer has become a test bed for projects and ideas. I thought that some accent lighting would be a cheap and easy way to add some excitement to the old beige box.

Finding the right lights turned out to be more difficult than I anticipated. I spent some time browsing eBay and several websites that sell PC modification parts, and all I could come up with were these silly USB light bars that pulse in response to music. That wasn't even close to what I wanted.

However, I eventually stumbled across which had exactly what I was looking for. Their mini cold cathode lights were the right size and at just $8 dollars for a two-bulb kit, the price was too good to pass up. In addition to the green CCFL kit, I ordered a strip of blue LED lights for a different project. In less than a week, I had received my order and was ready to rock and roll.

Green cold cathode light with 12V molex connector The cold cathode lights from Oznium were designed for automotive applications, which I gathered from the dozens of pictures of glowing cars on the website. Since cars and computers both use +12V DC power, I figured it would be a snap to adapt the mini fluorescent lights to my computer case project.

It was no trouble to crimp a molex connector on to the end of the two bare wires sticking out of the transformer. Now I'm not usually one to toot my own horn, but I did such an awesome job on the power connector that you'd think they came that way from the factory. Because there was no good place to mount an on/off switch (and because it would have made the project that much more complex) I decided to skip that part. The best solution seemed to be that that the lights would stay on whenever the computer was powered on. Keep it simple, as the old saying goes.

Next, I prepared to test my connection by hooking the light kit up to a spare power connector inside the computer. I held my breath as I hit the power button. I felt a little bit like Dr. Frankenstein watching his monster come to life as both lights illuminated with a beautiful green glow. Now, the only thing left to decide was where to mount the tubes.

Both light tubes in their final configuration. The goal was to have the green tubes light the inside of the computer case without having them in plain sight. This required some packing tape to mock up different positions inside the case before I found the perfect fit. The final configuration had one light mounted to the bottom of the power supply and the other light mounted above the intake fan.

To secure the lights in these unusual locations, I used the strip of 3M VHB (very high bond) adhesive tape that came with my LED lights. VHB is a special type of super-strong tape that is designed for permanent applications. It will not sag over time like other adhesives which made it perfect for this project.

Now, back to the lights. All that was left was to tidy up the wiring and put the case back together. The whole project was a fun exercise in wiring and cable organization. There, now doesn't that look much better?

-Trevor Freeman
04 September 2008


Return to Projects Page