I just finished cleaning the keyboard on my most recently acquired (i.e. third) 1200xl. All keys (including function keys) work 100% according to both the built-in keyboard test and actual test typing with AtariWriter. The only thing that doesn't work are the "control-f1" and "control-f2" keyboard disable and screen shut-off features. I know the "control" key is working because "control-f4" (int'l/graphics character set) works. And I know the f1 and f2 keys are working because I can drive the cursur around with them in BASIC. The "L1" led doesn't get power either when pressing "control-f1" which I believe it should. I tested the led, itself, and it works.
Also, if I run the following program: 10 pr.peek(764) 20 goto 10 I get values for the function keys, individually, and correct values for control-f3 and control-f4, but no independent value for control-f1 or control-f2.
Any thoughts?