A troubleshooting section is not a conventional FAQ. Instead of Q&A, you have a three-part structure: (1) symptom, (2) diagnosis, and (3) solution. Offer troubleshooting sections as a supplement to your FAQ.

Symptom

Start with the symptom (not a question), as described by the user (not an engineer).

Good: "I downloaded the software, but it won't start."
Bad: "Difficulty in launch."

Sum up the problem in terms that your guests would really use, so they can recognize their situation.

Diagnosis

Give your diagnosis of what may be going wrong, if you have any idea.

Identify the diagnosis with a subhead, setting it off, so the anxious user can skip this section, and the curious can learn to perform this analysis.

Solution

Break out the solution, too, with its own subhead.

Usually, this section requires numbered steps, if there is a concrete sequence of actions to perform.

But sometimes you're offering a handful of options, in a bulleted list. Only use numbers if the user must perform the steps in order.

Big trouble

If you face a really complicated problem, use a branching diagnostic approach.

In response to the problem, ask a question, and offer all possible answers as links.

When the user clicks one, offer the next logical question, and the next, and so on, until you are pretty sure you know what the problem is.

Then give the specific fix for that problem.

Branching diagnostics like this are wonderfully helpful.