After I bought plenty of Atari 1200XL computers they finally reached my home. Previously I already refurbished two of them as outlined in another post.

Now I've got special ones. One of them looked brown, small brown material has fallen out thru the louvres. The keyboard was mud and really ugly. So not really a candidate to plug power to and start gaming.

First action was to open the chassis within my bath tub to ensure nothing will survive or jump onto my artery by definding it's home 

The internal looked not really good, a lot of dead insects and biologic rests. I finally removed the mainboard and used fresh water to clean the housings. The mainboard was cleaned with a broom until it was clean. The shielding was highly rusty. After full disassembly of the housing by removing keyboard, pcb i recognized one key was broken.

After the housing was cleaned I prepared it for bleeching and finally it layed about 2 days in sun. Then it was washed again and all kind of cosmetic operations performed to get a clean white device. The plexiglas front was a little bit burned and scratched. With the right chemical cleaner the scratches were removed and the glas is now clean and looks like new. Some of the function keys still contained their plastic protection which I now removed as the surface looked scratched. The scratched keys without protection where polished with a special cleaner, too. Not all scratches are currently gone but it looks quite nicer than before.

The cartridge slot of the Atari 1200XL series contains all the time black scratches, I never saw a system without it. For that kind of scratches you'll need a special cleaning procedure.

I assembled the housing again and it now looked quite nice. Next step was to clean the keyboard, polish each key and repair the broken one. the root cause for the broken key was quite easy: it blocked and the plastic pin holding the keycap broke finally. So I opened the keyboard, removed the plastic tap and rasp the hole a little bit until the tap returned without blocking. By drilling a hole into the key caps on the bottom and an identical hole on the plastic tap allows to combine them by using a small part out of toothpick together with superglue. it perfectly fits together and the glue combine them for their whole life. 5 minutes later the key worked like new.

Cleaning of the mainboard required to remove the shielding. Underneath it was in good condition. To clean them up simple use a towel soaked in spiritus and lay it on top for a hour. The shielding itself must be polished and then you use graffith spray to recondition the shield.

If the device will work after power up will be highlighted in next thread. I simple have not tried it yet for time reason. The other Atari 1200XL delivered in same timeframe requires a similar procedure so I will test both to save time.