Hi Mike,
You could use a helper column and concatenate the data then use conditional
format to highlight identical lines.
Following assumes data in A1:F50 as per your post.
In cell G1 insert the following formula.
=A1&B1&C1&D1&E1&F1
Copy the formula to the bottom of the data.
Select the full range in column G
Select conditional format and select formula for the rule type.
Insert the following formula for the rule.
=COUNTIF($G$1:$G$50,G1)>1
(Note that $G$1:$G$50 must be absolute with $ signs and G1 is relative.)
Set the format required like yellow fill.
Then matching lines will be shown up with yellow fill. Note that if you have
multiple matching rows then all will be yellow and you will have to sort out
the matching ones but in 50 samples 6 wide the probability of that is low.