I am new to the site and only have abt three years in the industry. I had another tech tell me that you can diagnose alot just by temping (laser) the top of the hermetic compressor. He said all hermetics should run at between 110 to 135 degress F. He even uses that as a main factor to charge the unit. I had never heard of that before or read it. Can anyone expound on what he is talking abt? Thanks.