[Coco] Trying to get a KoKo2 working

[Chris Osborn]

I got a KoKo 2 off eBay a few days ago, and it boots up, but the keyboard doesn't work at all. I've been trying to hunt down schematics but so far have only found schematics for the CoCo 1 & 3, nothing for the 2.

I pulled out the logic probe to test the 6821, and I do see signals, but not like I'd expect. Pin 3 is stays high, and pin 12 is oscillating. I would expect since it should be scanning the matrix that several of the pins to be oscillating as it scans the matrix. Is the PIA dead, or could it be something else?