Further PDP-11/05 debugging -- core memory faults

I would just trace the tracks, both visually an with an ohmmeter, from the edge conector pin to the core mat and from the core mat to the diode array. Just in case. Incidneatlly, no matter what it says on the cover over the core mat, you can take it off quite easily without damage. Just don't drop it on the corse. If it is the core address wire in the mat, you may have big problems. Some of these mats had the cores cast onto the array of wires, no pre-made cores that were threaded with the wires. In which case, replacing the wire might be impossible. My first throught was 'have a go anyway. If you wreck the board, well, it doesn't work now'. And then I thoguth that no, you should treat it with care. Even if you don't have the skill to fix it now, you might do so i nthe future. Or somebody else might have a go. In any case, you don't want ot make thigns worse. -tony