|Re: The end of my 67|
Message #7 Posted by Tony Duell on 13 Dec 2004, 3:06 p.m.,
in response to message #4 by marais
The cathode driver doesn't generate the clock. In Classics, the clock is generated by the anode driver, but the 67 is not a classic inside, it's a Woodstock. And on Woodstocks (and for that matter Topcats and the 19C), the clock generator is in the ACT CPU chip.
If you're getting a sane display (0.00, for example), then the clock is running. In fact the ACT, ROM0, anode driver transistor array and cathode driver are all at least partially working.
Now, in the 67 the keyboard is scanned by the cathode driver outputs, and feeds into 5 inputs on the ACT chip. Since you've swapped out the logic board (including the ACT), I would assume the ACT is good (at least for the moment), and the cathode driver is doing something.
Have you checked for a short in the keyboard matrix (for example, a key that's electrically pressed all the time). I'm pretty sure that will disable the keyboard on these machines. If you have the pinouts and a 'scope or logic analyser, look at the 5 KA...KE pins on the ACT or on the keyboard-logic board connector. They should all be 'dead'. If you get a signal on one of them, you've got a key shorted.