Now that I have my apple 1 working, I found a Franklin Ace 1000 keyboard. I replaced all the foam pads in it, and cleaned the board. But when I hook it to the apple 1, the apple 1 doesn't boot anymore (we can guess the characters grid on the screen, but that's it, no chars). My cable work. I tested with 2 different cables (12cm and 50cm long) that both work with a "USB keyboard to Apple ][" adapter. The lock LED lights up tho.
I'm going to test the power consumption when I can. My first guess is it's pumping too much current. I already test for shorts in the cable socket and found nothing, beside some NC pins connected to +5v or ground, but since my cables don't do anything with those NC pins, it's not a problem.
Could be a dead chip or resistor/capacitor, but before unsoldering a bunch of things to test them, wanted to have an opinion on the issue. Maybe I'm missing something obvious.