My brother has a Qosmio G25-AV513 laptop and we want to hook it up to his 5.1 surround sound system. The system is a home theater system based around a Sony Dolby Digital/DTS receiver. Supposedly the headphone jack on the laptop doubles as a S/PDIF output per the instruction manual, and thus I have a 3.5mm to RCA cable designed for coaxial digital signals connecting the computer to the receiver. The manual says this is an optical S/PDIF output, however it seems this is impossible because it is a standard 3.5mm connector. The receiver gets no signal, and thus no sound is produced. He mainly wants this for listening to music, but also for when watching downloaded video files in Media Player. Does anyone know how to enable the digital signal so that this setup will work, or have any other suggestions?