Docedison:
Some investigative work with a DMM should straightaway put you on to the bad parts, a slightly scorched smell may well be present too and is a good indicator of parts that have been stressed..
He knows where the burned-beyond-recognition resistor is. He wanted help figuring out the correct replacement value.
Oh, one other option: If the resistor is near an identifiable chip you might find the application notes for that chip provide a recommended value for that resistor.