From what you are describe, I think you have a very simple and common (I’m certainly guilty) mistake. In taxonomy-computer.php, you have put your code after while ( have_posts() ) : the_post();. The result is that it executes not once, but every time a “computer” post is displayed.
To fix the problem, you need to move your code and put it BEFORE while ( have_posts() ) : the_post();.
A taxonomy template is a form of archive template; it is going to display multiple posts. In your case, taxonomy-computer.php is going to display each every post that has been been tagged as “computer”. If the goal is to display the FAQ at the top of the page, followed by each of the “computer” posts below, then your FAQ code needs to be inserted before the template starts displaying the “computer” posts (i.e. before while ( have_posts() ) : the_post();).
Just where you put the code depends on how you want to format the template. That part is up to you.