You are listening to an audio CD on your desktop computer at work, like all the employees do. One morning, all employees receive an e-mail from the corporate services asking not to play loud music on the desktops. However, no restriction is placed on listening to music using a headphone. You plug your headphones into the jack on the front of the CD-ROM drive, but you hear no sound. You adjust the volume control on the front of the CD-ROM drive, but still hear no sound. You turn the speakers back on and can hear the music again. Which of the following could be the likely cause of this issue?