Detecting damaged characters in a UTF-8 encoded text file

I have a text file that has been edited with the wrong character encoding and therefore has some mojibak and corrupt characters on some lines when I open it with UTF-8. What scripting language will be most effective in detecting these corrupted symbols? Perl is not an option. I am basically trying to find a way to scan through a text file using a script and output the line numbers and possibly offset where the damaged character is found. How should I do it? I was thinking about using AWk, but I don't know what regex to use to find corrupted characters. If I could be directed in the right direction, that would be great.

More complete input:

I want the script to tell me the number of the damaged characters line, which will be the fifth line in the above example. Also, there are different languages ​​in the text file. I have English Chinese, French, Spanish, Russian, Portuguese, Turkish, French_Euro, German, Dutch, Flemish, Korean, Portuguese_Moz. And I have some special characters like # and! and ***

I used this if statement to get the above output:

if($1 ~ /[^\x00-\x7F]/){
print NR ":" , $0 > "output.txt";
count++;
}