Jed118 wrote:

for the time being, does anyone know where DIN pin 1 and 2 (CLK and DAT) go to on the keyboard controller?

What I did for something like that was just connect one end of the multimeter to the socket, and slowly slide the other end across the DIP socket, one side then the other. With the multimeter in continuity mode, it'll beep as soon as you hit the pin the socket is connected to. If you don't get any beep, there's your faulty pin. If all pins get beeps, the socket is connected to the controller without a problem. For this purpose, it's not really important to know which pins go where, just that they are all connected somehow to the chip.

From memory a keyboard error is different to a 'no keyboard detected' error, so it looks like it could be some other pins on the keyboard controller that are suspect.

Looks like I'm going to be trying this again on a new arrival - a 286 from Germany. Same problem, corroded traces. I'll have to look carefully for the broken traces!

Edit - found them, under the keyboard socket. After I removed it (and neutralized the corrosion) and redid a couple traces, everything worked out!

Had a chance to work on a Tomato TD60C motherboard (Harris CS80C286-20 CPU, Citygate D90-272 for chipset) that had a battery leak.
The corrosion ate away one pcb trace for keyboard clock line, and destroyed one pin on the onboard dram chip.
Some soaking in the vinegar, cleaning with IPA, a bit of soldering - and it's working 😀
Populated SIMM slots with some ram sticks, now it has 5MB total ram. Probably it never saw that amount of ram in its life.

Didn't save any photos of the initial mess.