HP Dc7900 Service Reference Guide: HP Compaq dc7900 Business PC - Page 265

Table D-6 Solving Display Problems (continued) Dim characters. Cause The brightness and contrast controls are not set properly. Cables are not properly connected. Solution Adjust the monitor brightness and contrast controls. Check that the graphics cable is securely connected to the graphics card and the monitor. Blurry video or requested resolution cannot be set. Cause Solution If the graphics controller was upgraded, the correct graphics Install the video drivers included in the upgrade kit. drivers may not be loaded. Monitor is not capable of displaying requested resolution. Change requested resolution. Graphics card is bad. Replace the graphics card. The picture is broken up, rolls, jitters, or flashes. Cause The monitor connections may be incomplete or the monitor may be incorrectly adjusted. Monitor needs to be degaussed. Solution 1. Be sure the monitor cable is securely connected to the computer. 2. In a two-monitor system or if another monitor is in close proximity, be sure the monitors are not interfering with each other's electromagnetic field by moving them apart. 3. Fluorescent lights or fans may be too close to the monitor. Degauss the monitor. Refer to the documentation that came with the monitor for instructions. Image is not centered. Cause Position may need adjustment. Solution Press the monitor's Menu button to access the OSD menu. Select ImageControl/ Horizontal Position or Vertical Position to adjust the horizontal or vertical position of the image. "No Connection, Check Signal Cable" displays on screen. Cause Solution Monitor video cable is disconnected. Connect the video cable between the monitor and computer. CAUTION: Ensure that the computer power is off while connecting the video cable. Solving Display Problems 253