Troubleshooting Your Computer 3-293. Make sure the external monitor’s video cable is firmly connected to the com-puter’s external monitor connector, and then verify that the monitor’s powercable (if it has one) is firmly plugged into an AC power source. Make sure themonitor is turned on.4. Check the monitor cable for bent pins.5. Turn off the computer, wait a minute, and then turn the computer back on. Adjustthe monitor’s brightness and contrast controls. Is the monitor readable?Allow one minute for the computer to initialize its components.Yes. The problem is resolved.No. Go to step 6.6. Raise your computer’s display into viewing position, if necessary, and press to switch the video image from the external monitor to the display.7. Use the down-arrow or up-arrow key combination to adjust thebrightness. Is the full display readable?Yes. The external monitor may be defective. Go to step 8.No. The video controller on the system board may be defective. Call Dell for tech-nical assistance. (See Chapter 5, “Getting Help,” for instructions.)8. Turn off the computer and any attached peripherals. Disconnect all peripheralsfrom the computer. Attach another external monitor to the computer.If you do not have another external monitor, call Dell for technical assistance.(See Chapter 5, “Getting Help,” for instructions.)9. Reboot the computer, and adjust the monitor’s brightness and contrast. Is themonitor readable?Allow one minute for the computer to initialize its components.Yes. The original monitor is defective. Call Dell for technical assistance. (SeeChapter 5, “Getting Help,” for instructions.)No. Call Dell for technical assistance. (See Chapter 5, “Getting Help,” forinstructions.)7URXEOHVKRRWLQJWKH6HULDODQG3DUDOOHO3RUWV This section provides a procedure for troubleshooting the computer’s serial and paral-lel ports (shown in Figure 3-4) and any attached peripheral devices.If a system error message indicates a port problem or if equipment connected to aport seems to perform incorrectly or not at all, the source of the problem may be anyof the following:á A faulty connection between the I/O port and the peripheral deviceá Incorrect settings for system setup options