That works!!!
Each audio jack on this motherboard can be LINE-IN jack. The blue audio jack at rear side of motherboard is used to be LINE-IN jack as default. Thus, please open VOLUME CONTROL panel under WINDOWS, then choose properties option; then you will find "Rear Blue In" option (If you want to use other audio jack to be LINE-IN, please chooes the proper "color" option). Please make sure the option is checked. After back to the volume control panel, you can find the Rear Blue In volume control option, please increase the volume by the slide bar.