Hello, Geekhack!
I recently got a Focus 5001 keyboard off of eBay, and maybe I should have looked at the pictures a bit closer when I was buying it, because when it came in the mail, the keyboard was chock-full of dust and the Alps switches were basically sandpaper. I linearized and lubed the switches and their housings, and while the switches were cleaned enough to be tolerable, I tested it out on my PC.
The problem I have is that the macro key doesn't do anything. It sends a strange scancode that appears as "<" on my PC, and pressing a macro key with the macro key activates the default option, i.e. copies of the regular function row. So if I press a left-handed key that said "F1", I get the F1 scancode as if I pressed the top keys. However, if I press the turbo key in tandem with the function row, the function keys don't send any scancodes, although the turbo functionality isn't visible on my computer. Another problem that I have is that the keyboard doesn't send any characters unless I fiddle with the AT/XT switch. The calculator works perfectly, no matter what happens to the keyboard. My particular Focus model uses the coin-cell battery type, so corrosion isn't an issue. I wonder if it's an aging controller, or if it's another problem that appears because of Focus's cost-cutting.
Since I'm replacing the Alps switches in this board with Matias clicky switches in the near future, should I also invest in a Teensy and replace the chips on the board?
