[user181]

The service manual includes board views with the component reference designators, and legends for their location on the coordinate grid. That being said, the scan resolution of the document is not wonderful, so it's tough to read in places. But, having the legend with the coordinates should help your narrow things down in that region of the board.

You ought to seek out a better copy of the service manual. Maybe Sams has it, and you could ask them to make a better scan if necessary (they've done that for me in the past).