Dell OptiPlex 755 User's Guide - Page 343

E N S U R E T H A T T H E S U B W O O F E R A N D T H E S P E A K E R S A R E T U R N E D O N - See the setup diagram supplied with the speakers. If your speakers have volume controls, adjust the volume, bass, or treble to eliminate distortion. A D J U S T TH E W I N D O W S V O L U M E C O N T R O L - Click or double-click the speaker icon in the lower-right corner of your screen. Ensure that the volume is turned up and that the sound is not muted. D I S C O N N E C T H E A D P H O N E S F R O M T H E H E A D P H O N E C O N N E C T O R - Sound from the speakers is automatically disabled when headphones are connected to the computer's front-panel headphone connector. TE ST T H E E L E CT R I C A L O U T L E T - Ensure that the electrical outlet is working by testing it with another device, such as a lamp. E L I M I N A TE P O S S I B L E I N T E R F ER E N C E - Turn off nearby fans, fluorescent lights, or halogen lamps to check for interference. RUN THE SPEAKER DIAGNOSTICS R E I N S T A L L T H E S O U N D D R I V E R - See "Drivers" on page 356. R U N TH E H A R D W A R E TR O U B L E S H O O T E R - See "Troubleshooting Software and Hardware Problems in the Microsoft® Windows® XP and Microsoft Windows Vista® Operating Systems" on page 358. No sound from headphones C H E C K T H E H E A D P H O N E C A B L E C O N N E C T I O N - Ensure that the headphone cable is securely inserted into the headphone connector (see the front and back views for the appropriate computer). A D J U S T TH E W I N D O W S V O L U M E C O N T R O L - Click or double-click the speaker icon in the lower-right corner of your screen. Ensure that the volume is turned up and that the sound is not muted. Video and Monitor Problems CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide. NOTICE: If your computer came with a PCI graphics card installed, removal of the card is not necessary when installing additional graphics cards; however, the card is required for troubleshooting purposes. If you remove the card, store it in a safe and secure location. For information about your graphics card, go to support.dell.com. The screen is blank NOTE: For troubleshooting procedures, see the monitor's documentation. The screen is difficult to read CHECK THE MONITOR CABLE CONNECTION - • Ensure that the monitor cable is connected to the correct graphics card (for dual graphics card configurations). • If you are using the optional DVI-to-VGA adapter, ensure that the adapter is correctly attached to the graphics card and monitor. • Ensure that the monitor cable is connected as shown on the setup diagram for your computer. • Remove any video extension cables and connect the monitor directly to the computer. • Swap the computer and monitor power cables to determine if the monitor's power cable is defective. • Check the connectors for bent or broken pins (it is normal for monitor cable connectors to have missing pins). Solving Problems 343