Wait what? Don't. Answer in answers. See put slightly more sarcastically: Comment UI not friendly enough
Now I think you're more getting at the issue I'm trying to cover in this question, which is still under discussion: When is it appropriate to instruct a user on precise debugging steps to solve a problem?
If you're helping the user research a question and you don't really know what's going on, post a comment. If you have a step to take that you reasonably expect will get the user over the problem, post as an answer.
Side-note: Even on meta it's better to have a "problem to solve." I thought this was easy to answer and have a reasonable guess as to what spurred this problem so I answered, but you really ought to explain what situation prompted you to become unsure of this.