Using a variable Wild Card parameter to SELECT from several FIELDS with OR

Using a variable Wild Card parameter to SELECT from several FIELDS with OR

I am trying to create a more versatile search capability for my website's
repair videos. I am using this to break the search field POST into wild
card words.
$words = EXPLODE(" ",$search_term);
FOR($i=0;$i<count($words);$i++){$query_string .= "videos.Title LIKE
'%".$words[$i]."%' AND ";}
Then
SELECT * FROM videos WHERE $query_string;
This works for one FIELD "videos.Title". I would like to search more
fields in the data for results. It works with one word but two or more
words causes a problem...
I was trying this:
SELECT * FROM videos
WHERE Title LIKE $query_string
OR Description LIKE $query_string
OR PartNumber LIKE $query_string
OR KeyWords LIKE $query_string
OR Brand LIKE $query_string
OR Item LIKE $query_string
OR Models LIKE $query_string;
I tried:
SELECT * FROM videos
WHERE Title LIKE $query_string
OR (Description LIKE $query_string)
OR (PartNumber LIKE $query_string);
-Did not work-
I also tried
SELECT * FROM videos WHERE '$query_string' IN (Title, Description,
PartNumber)
-Did not work-
Any Ideas? Thanks for the help!