You look foolish if equipment malfunctions again an hour after you repaired it. Maybe you didn't do anything wrong that set a landmine for another failure to occur. But if you fixed only what the issue that precipitated the trouble call, you can easily leave a landmine for yourself.

The adage, "Where there's smoke, there's fire" tends to prove itself in the world of industrial equipment repairs.

A classic mistake that sometimes actually results in fire is simply replacing a blown fuse without determining why it blew. A fuse isn't just some inadvertent weak link that eventually goes past its freshness date and opens. A fuse opens because of a problem. Yes, sometimes a transient problem can cause a fuse to blow, so positively identifying the problem isn't always possible. But you need to rule out other causes before replacing the fuse.

For each major piece of equipment, develop quick checklists to help you discover issues before walking away from a repair.