Volvo Repair: A/C 1994 Volvo 940, worse case scenario, volvo 940

Question
My A/C wasn't working so I brought it in for a re-charge 04.20.05. It worked great when I left, and it has been cool the last few weeks. It was warm enough to use yesterday and when I turned it on, no cool air! They tested the system and put dye in it. I see no visible leak with the dye. What could this be? What is the worse case scenario in $? Thanks, Shawn.  

Answer
Hello Shawn,  Well your ststem hold almost 2lbs.of freon, and with the dye to have leak away with such short usage,I would be looking at the compressor.If it leaked as a gas you won't always see dye stain.The evaporator can be accessed to get a visual,the drain can have only slight trace of dye because of the condensation wash. Yellow glases and ultraviolet lamp will be needed to see dye.The darker you can get the checked areas the better you'l see the dye.It will run $6/800 ,compressor the lesser of the estimate.Thank you and good hunting!  PKD