Compaq 1200US Presario Select 1200 Series Maintenance and Service Guide - Page 22

Maintenance & Service Guide Presario Series Models: 1246, 1247, 1277, 1278, and 1279 | Home Page | Notice | Preface | Product Description | Troubleshooting Illustrated Parts Catalog | Removal & Replacement Procedures | Specifications Pin Assignments | Battery Pack Operations Troubleshooting Without Diagnostics Solving Minor Problems Some minor problems and possible solutions are outlined in the following tables. If the problem appears related to a software application, check the documentation provided with the software. Solving Audio Problems Some common audio problems and solutions are listed in the following table. Problem Computer does not beep after the Power-On Self-Test (POST). Solving Audio Problems Probable Cause This is typical; it indicates successful completion of the Power-On Self-Test (POST). Solution(s) No action is required. Solving Battery Pack and Battery Gauge Problems Some common causes and solutions for battery pack problems are listed in the following table. The "Solving Power Problems" section in this chapter may also be applicable. Problem Solving Battery Pack and Battery Gauge Problems Probable Cause Solution(s) Computer won't turn on when battery pack is inserted and power cord is unplugged. Battery pack is discharged. Connect the computer to an external power source and charge the battery pack. Computer is beeping and battery LED icon is blinking. Battery charge is low. Replace the battery pack with a fully charged battery pack. Check the battery connectors on the system board to verify they are evenly spaced and that they are not bent or broken. Immediately save any open file(s). Then do any one of the following: q Connect the computer to an external power source to charge the battery pack. q Turn off the computer or initiate Hibernation until you can find another power source or charge the battery pack. Computer battery LED icon (front on the Volume is turned down too low. unit) blinks to indicate low battery condition, but computer does not beep. Battery LED icon doesn't light and battery pack won't fast charge. Battery pack is already charged. Battery pack was exposed to temperature extremes. Battery pack is at end of its life. You have to set the date and time every RTC battery is dead. time you turn on the computer. Adjust the volume. No action is necessary. Allow time for the battery pack to return to room temperature. Replace battery pack. Replace the RTC battery. Problem Battery charge does not last as long as expected. Battery pack is warm to the touch after charging. Battery pack operating time is far less than the documented average operating time. Probable Cause Solution(s) Battery is being exposed to high temperatures or extremely cold temperatures. Keep the battery pack within the recommended operating temperature range 50° F to 104° F (10° C to 40° C) or recommended storage range 4° F to 86° F (-20° C to 30° C ). Recharge the battery pack. Battery has partially self-discharged. Recharge the battery. Discharge the battery completely and then recharge it. Power management is disabled. Set a power management level in Computer Setup. An external device or PC Card is draining Turn off or disconnect external devices the battery. when not using them. Normal warming has occurred due to charging. No action is required. Power management is turned off or disabled. Enable power management in Computer Setup and in Windows Power Properties. An external device or PC Card is draining Turn off or disconnect external devices the battery. when not using them. Battery pack has partially selfdischarged. Condition the battery pack by fully charging, fully discharging, then fully recharging it. To maintain the charge, leave battery packs in the computer when it is connected to external power. Battery pack is being exposed to high temperatures or extremely cold temperatures. If the computer is disconnected from external power for more than two weeks, remove battery packs from the computer to reduce the discharge rate. Keep the battery pack within the recommended temperature ranges. Operating: 50° F to 104° F (10° C to 40° C) Storage: -4° F to 86° F (-20° C to 30° C ) Recharge the battery pack. Solving CD Drive Problems Some common causes and solutions for CD drive problems are listed in the following table. Problem CD drive cannot read a compact disc. Solving CD Drive Problems Probable Cause Solution(s) Compact disc is upside down or is improperly inserted in the CD drive. Open the CD loading tray, lay the compact disc in it (label side up), then close the tray. CD is CD Plus or Pregap/Track 0 type. Cannot read these type CDs in 24x. Remove the CD. Solving Diskette and Diskette Drive Problems Some common causes and solutions for diskette and diskette drive problems are listed in the following table. Solving Diskette and Diskette Drive Problems Problem Probable Cause Solution(s) Diskette drive cannot write to a diskette. Diskette is write-protected. Disable the diskette's write-protect feature or use a diskette that is not write-protected. Computer is writing to the wrong drive. Check the drive letter in the path statement. Not enough space is left on the diskette. Use another diskette. Drive error has occurred. Run Computer Checkup from the Compaq Diagnostics diskette. Diskette is not formatted. Format the diskette. At the system prompt, enter FORMAT A: Diskette drive cannot read a diskette. The wrong type of diskette is being used. Use the type of diskette required by the drive. Diskette has a bad sector. Copy files to hard drive or another diskette. Reformat bad floppy. Drive error has occurred. Run Computer Checkup from the Compaq Diagnostics diskette. Diskette is not formatted. Format the diskette. At the system prompt, enter FORMAT A: Cannot boot from diskette. Bootable diskette is not in drive A. Put the bootable diskette in drive A. Diskette Boot has incorrect setting in Run Computer Setup and set diskette Computer Setup. as first to boot. Solving Display Problems This section lists some common causes and solutions for computer display and external monitor problems. You can perform a monitor self-test on an external VGA color or monochrome monitor by disconnecting the monitor from the computer. To do so, complete the following steps: 1. Turn off the monitor. 2. Turn off the computer. 3. Disconnect the monitor signal cable from the computer. 4. Turn on the monitor and allow it to warm up for one minute. The display should be white. A narrow black border may also appear on the left and right sides of the display. Either of these displays indicates that the monitor is working properly. Problem Screen is dim. Solving Display Problems Probable Cause Control for brightness or contrast (if applicable) is not set properly. Solution(s) Adjust the Brightness of the display by using Fn + F7 (¯ ) or Fn + F8 (- ). Adjust the Contrast of the display by using Fn + F5 (¯ ) or Fn + F6 (- ). Screen is blank. Computer screen is in direct light. Screen save was initiated by Power Management due to lack of user activity. Display has overheated. Display is blank and the Suspend icon is System is in Suspend mode. flashing. Internal display is blank and the screen on an external monitor displays information. Display function was switched to the external monitor. Tilt display or move computer. Press any key or touch the Touch Pad. If computer is in direct sunlight, move it and allow it to cool off. Press any key or touch the Touch Pad. Use Fn + F2 to switch between LCD or CRT. Problem Probable Cause Solution(s) Internal display flashes or has garbled characters Using 1024 × 768 or higher when computer is connected to external monitor. resolution on external monitor and have toggled back to internal display, which supports up to 800 × 600. Restart the computer. The light tubes on the edge of the display panel do not light up at all and Power-On Self-Test (POST) completes when the unit is powered up.** Improper backlight or display cable connections Replace the display assembly. Defective inverter board. Replace the display assembly. Defective display cable. Replace the display assembly. Defective display panel. Replace the display assembly. Defective system board. Replace the system board. The light tubes on the edge of the display panel do not light up at all and Power-On Self-Test (POST) does not complete when the unit is powered up.** Backlight (brightness) cannot be adjusted with Fn + F7 (¯ ) or Fn + F8 (- ).*** Defective system board. Improper display cable connections. Defective inverter board. Replace the system board. 1. Reseat the display cable to the system board. 2. Replace the display assembly. Replace the display assembly. Defective display cable. Replace the display assembly. Defective system board. Replace the system board. Contrast cannot be adjusted with Fn + F5 (¯ ) or Fn + F6 (- ). Improper display cable connections. 1. Reseat the display cable to the system board. Defective inverter board. 2. Replace the display assembly. Replace the display assembly. Defective display cable. Replace the display assembly. Defective system board. Replace the system board. ** This problem indicates that the backlight or its power circuitry has failed. Since you cannot observe the POST result on the display panel when the backlight is not functioning, connect the unit to an external monitor before powering the unit up. If an external monitor is not available, verify that POST completes by opening and closing the display, listening for the single or double beep, and watching for the LEDs turn on at the front of the computer. Problem This display panel has a continuous pattern across it (e.g., a "jailbars" pattern), has a single color on it, or has garbled graphics across the entire panel. This failure is for patterns across the entire panel (not just on one section). Probable Cause Improper display cable connections Defective display cable. Solution(s) Reseat the display cable to the following until the problem is solved: 1. System board 2. Display assembly Replace the display assembly. Defective inverter board. Replace the display assembly. Ghost bars extending from graphics on the display. Defective system board. Replace the system board. Common characteristic of STN displays. 1. Change the background colors. 2. Adjust the Contrast of the display by using Fn + F5 or Fn + F6 . A single line, small group of lines, or block appears on the display panel. This failure occurs in only a section of the display panel. Defective display panel. Replace the display assembly. To perform a "self-test" on an external VGA color or monochrome monitor, complete the following steps: The NOTE: screen should be white. A narrow black border may also appear on the left and right sides of the display. Either of these displays indicates that the monitor is working properly. Solving Hard Drive Problems Some common causes and solutions for hard drive problems are listed in the following table. CAUTION: To prevent loss of information, always maintain an up-to-date backup of your hard drive at all times, in case of errors or failures. Problem Reading hard drive takes an unusually long time after restarting the computer. Hard drive error occurs. Hard drive does not work. Solving Hard Drive Problems Probable Cause System entered Hibernation due to low battery condition and is now exiting from it. Hard drive has bad sectors or has failed. Hard drive is not seated properly. Solution(s) Give the system time to restore the previously saved data to its exact state before Hibernation. Run Computer Checkup. Turn off and unplug the computer, remove the battery pack, and remove and then reinstall the hard drive. Solving Hardware Installation Problems Some common causes and solutions for hardware installation problems are listed in the following table. Solving Hardware Installation Problems Problem Probable Cause Solutions(s) A new device is not recognized as part of the computer system. Cable(s) of new external device are loose or power cables are unplugged. Ensure that all cables are properly and securely connected. Power switch of new external device is not turned on. Turn off the computer, turn on the external device, then turn on the computer to integrate the device with the computer system. Device is not seated properly. Turn off the computer and reinsert the device. Solving Keyboard/Numeric Keypad Problems Some common causes and solutions for keyboard/numeric keypad problems are listed in the following table. Solving Keyboard/Numeric Keypad Problems Problem Probable Cause Solution(s) Embedded numeric keypad on computer keyboard is disabled. Num Lock function is not enabled. Press the Shift+NumLk keys to enable the Num Lock function and embedded numeric keypad. The Num Lock icon on the status panel turns on. Embedded numeric keypad is disabled and Num Lock function is on. External numeric keypad is connected to the computer. Disconnect the external numeric keypad from the computer. Solving Memory Problems Some common causes and solutions for memory problems are listed in the following table. Problem Memory count during Power-On Self-Test (POST) is incorrect. Solving Memory Problems Probable Cause Solution(s) Optional memory expansion card Ensure that the optional memory is installed incorrectly, expansion card is installed correctly. is incompatible with the computer, or is defective. "Out of Memory" message is displayed on the System ran out of memory for the screen or insufficient memory error occurs application. during operation. Check the application documentation for memory requirements. Install additional memory. Too many TSR (terminate-and stay- Remove from memory any TSR resident) applications are running. applications that you do not need.