Task: Fix an Atari 8-Bit Computer Keyboard by Replacing the Mylar Membrane
Needed: Screwdriver, mylar membrane
Time: 15-30 mins
Introduction
There were a variety of keyboard styles and technologies that were used in the entire Atari 8-bit line of computers. Some are mechanical and some use pressure on a mylar membrane to register a keystroke. Mylar membranes are notorious for wearing out and developing bad contacts and bad traces. A classic symptom of this is a set of keys that will stop working. For me, I discovered my Atari 130XE functions keys (Help, Start, Select, etc.) had stopped working. Upon opening up the Atari I discovered it was indeed a mylar-based keyboard that had started to look a little worn. It is possible to fix these with special conductive paint to fill in damaged traces. However, I opted to purchase a brand-new keyboard because they are new and relatively inexpensive.
Instructions
The first step is to order a newly made mylar membrane. I got mine from The Brewing Academy for $15. Mylars for XL and XE computers are also available from 8-Bit Classics for a bit more money.
The second step is to open up the Atari by removing the screws on the bottom and carefully removing the keyboard by unplugging the connector. The bottom plate of the keyboard can then be gently removed with a set of smaller screws.
Once the bottom is off you can remove the mylar and replace it with the new one. Note that the mylar keyboard has a set of small rubber cups (green circles in photo below) that provide some resistance when a key is pressed. Be careful not to lose any of these and make sure they are all correctly seated when replacing the mylar.
The final step is to replace the bottom keyboard plate and the reinstall it in the Atari. Be careful replacing the ribbon connector. It is easy to bend this and break traces. You can the reattach the top and bottom of the Atari with the screws.
Comments
This is a pretty easy fix if you don’t mind purchasing a new mylar.
Here is a post on Atari Age about 600XL and 800XL keyboard variants.