Tiido wrote:Problem is most probably some connection to a KBC if another KBC won't work in there. If you can borrow one from another board then do so, if it still gives the same error you got a broken trace or a via somewhere.
Pins 1-2-5 are definitely connected to the KBC, solid. If the circuit I posted above is also logical, then there should be no issue between the socket and the KBC. Aside from the blown fuse, which I shorted with a botch wire and that only served to blink the keyboard lights momentarily durin boot.
Say, tonight I will replace the blown fuse with these:
https://www.direnc.net/3a-250v-direnc-tip-sigorta
If that does not work, I will then remove the KBC and replace it with a DIP-40 socket, then install a KBC from one my 486 motherboards, such as this one:
83C42 to replace 80C42 should probably work, it only seems to add PS/2 functionality etc.
And if that doesn't work, well I don't know which traces and vias to look at - any pointers about how the KBC and chipset/CPU are connected?
Retronautics: A digital gallery of my retro computers, hardware and projects.