Hiding Posts in Website

Hi Guys,

I have a question that I really need help with. Ok so I have the following piece of code in my theme-functions.php file

function exclude_category($query) {
if ( $query->is_home || $query->is_archive) {
$query->set('cat', '-481');
}
return $query;
}
add_filter('pre_get_posts', 'exclude_category');
?>

What this code does is exclude or hide a post that is listed under the Product/Tech News section of our site. Now when I put it in everything works fine and theres no issues but if I create 5 posts under Tech/Product News and then click the Category name to show all the posts under that category it fails and just shows a blank page as if there is no posts under that category. How can i edit the above code to hide the posts in the site and search results etc. but not from the category view? I hope this makes sense.

[No bumping. If it’s that urgent, consider hiring someone.]