Anyone who owns a computer from the 1980s like a Commodore Amiga or an Apple II knows all to well that over time the computer's case will turn yellow. Many computer cases from that time were "brominated", a process of adding bromine to ABS plastic to act as a fire retardant. The yellowing occurs when the bromine in the plastic is exposed to UV light, like the sun.
A crafty retro computer enthusiast realized that covering the yellowed plastic in hydrogen peroxide and exposing it to UV light reversed the yellowing of the bromine and cleverly named it retr0brighting.
I own a large collection of retro computers. I repair them, restore them and then store them away in my collection. I recently added an Amiga 500 to my ever growing Commodore collection and true to the effects of time it was dirty, grimey and quite yellow.
I'm not sure what kind of life this Amiga had before it came into my possession, but as you can see from the pictures, it was a hard one. It is yellow, dirty and has dried paint spots on it; no way to treat a classic computer.
There is no way I would let a computer like this suffer any longer. Time to roll up my sleeves and bring it back to its original glory.
Our first step is to flip over the Amiga 500 and remove all of the screws on the bottom and put them somewhere safe. Next we gently remove the top off of the Amiga revealing the keyboard, motherboard and floppy drive.
In order to remove the keyboard you have to unplug the connector on the motherboard and unscrew the grounding strap that is connected to the floppy drive. The keyboard will now slide right out.
Next, you want to remove the floppy drive which has a ribbon and power cable connected to the motherboard and it too will come right out. You will want to pop out the floppy eject button as this too can be cleaned and restored.
Lastly, the shield encased motherboard will come right out leaving nothing but the bottom shell.
Now we can put the upper and lower case components aside and begin work on the Amiga's keyboard.
Part of the restoration process is cleaning and de-yellowing the keys on the keyboard, so these need to be popped off. You can do this by applying gentle pressure under each key with a flat tool or spudger. Be very careful as under each key is a spring and you don't want to lose any of them.
Some of the longer keys like the spacebar, shift keys and the return key also contain a bar that is used to balance the key. Be extra careful when removing these keys.
We now need to seperate the small electronics board and metal backing from the keyboard. This will give us access to the switches and the black plastic keyboard frame so that it can be cleaned properly.
There are 4 screws holding the electronics board to the back of the keyboard and a small ribbon connector that needs to be freed. In order to separate the rest of the components, you need to remove what seems like 100 small screws on the back side.
Once the metal backing has been removed, a thin green conductive membrane will be exposed. This membrane is what registers keyboard input. Carefully remove the membrane and place it somewhere safe.
Carefully flip the black plastic keyboard component over on a table, all of the switches should fall right out. All of them are identical with the exception of one blue one that is used by the Caps Lock key. Try not to lose any of them as they are very hard to replace.
On the underside of the keyboard casing you will find an LED that is used to indicate whether the Caps Lock key is engaged. This is held in place by friction and it can be easily removed.
Now that we have disassembled the Amiga 500, we can move on to cleaning and de-yellowing all of the plastic components.
Cleaning and Retr0brighting
Before we move on to the de-yellowing phase, we want to make sure that our plastic components are free of dirt and grime. Remember, this computer is over 20 years old and looks like it was used heavily. All of those years are bound to take a toll on our Amiga 500.
I personally like to soak the components in a warm bath with some Oxiclean, but dish soap works as well. Oxiclean does a fantastic job of breaking down the dirt and grime so that you don't have to scrub components that are already quite old and maybe fragile. The amount of Oxiclean you should use depends on the amount of water you use. I have a very large laundry tub so I added about 1/2 a cup of Oxiclean to the warm water. Don't over do it with the Oxiclean as it can stain the plastic and make sure that it has been fully dissolved by stirring it. Take it from me, I have ruined old computer parts by using way too much Oxiclean.
After soaking for about 30 mins, I use a cloth to make sure all of the dirt and grime has been washed away from the surface and then rinse the components fully in cold water. I let them air dry for about 24 hours to make sure all the water has evaporated from all the nooks and crannies.
There are various recipes online that show you how to make your own retr0bright paste, but you could just head over to your local beauty supply store and pick up some creme developer that is ready to go.
If you live in the US, Canada or the UK then you can visit your local Sally Beauty and pick up their Salon Care 40 volume creme developer which already contains the right amount of hydrogen peroxide and comes as a creamy paste; all ready to go.
We now need to cover all our components evenly with retr0bright and wrap them up in shrink wrap. We do this in order to prevent the retr0bright from evaporating, which would leave us with blotches and an uneven job.
The key to the reversing process is UV light. The hydrogen peroxide reacts to the UV light and de-yellows the plastic. The best and quickest way is to use the sun which is a great producer of UV. If you live in a part of the world that doesn't get a lot of sun or it's winter and too cold to place the stuff outside (you don't want the retr0bright freezing) then a UV lamp will work as well, but the process will take longer.
I have used both the sun and artificial UV light to retr0bright various computers over the years. I generally get great results in 3-4 hours of direct sunlight and get the same results after 24 hours using a UV light. Check in on the parts every few hours, especially if you are using a UV light to make sure the retr0bright doesn't dry out or evaporate.
The next step in the process after the parts have soaked up some UV is to thoroughly rinse and wash the components with water and a mild soap. You want to make sure you remove all of the retr0bright solution; pay close attention to the underside of the key caps.
Once the components are dry, you can start the reassembly process following the same steps you used to take the Amiga 500 apart. Remember to reinsert the Caps Lock LED, the conductive keyboard membrane and the floppy eject button.
As you can see from the picture above, we are left with a refreshed Amiga 500 ready to provide countless hours of retro gaming fun!