[Vipergrün]

I've been in IT for 26 years. Based on my experience as a manager, people either have it or they don't. Troubleshooting requires a logical and methodical thought process, as well as some common sense and intuition. Common sense cannot be learned, IMHO. I've managed the type you mention, but for a short period of time. I'd put him on a PIP with milestones, then say cya if he doesn't improve.