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Compaq Q2009 20 inch Diagonal Widescreen LCD Monitor support

Monitor or TV is Blank after Starting the Computer

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This document pertains to HP and Compaq desktop computers.
This document is about troubleshooting a video connection from a monitor (or a TV being used an a monitor) to a personal computer. If you have a computer that has the monitor built-in, such as a HP or Compaq All-in-One PC or HP TouchSmart PC, see Screen is Blank after Starting the Computer .
This document will help you determine if the blank screen is being caused by the computer hardware, the video signal to the monitor, or the monitor itself.

Before you begin

Check the following items before using the steps in this document:
  • Make sure the monitor has power and the power light comes on when the power button is pressed. If the light on the monitor remains off, the monitor is not receiving power from either the wall outlet or the power adapter.
  • If you have a flat panel LCD monitor, unplug the monitor power cable, wait about 30 seconds, reconnect the cable and then turn on the monitor. This resets the electronics on the monitor.
  • If the monitor has a detachable video cable, obtain a second monitor cable for testing purposes in case the cable is bad.
  • Disconnect all connected devices except the mouse, keyboard, and monitor. This includes removing thumb drives and camera-type memory cards from card reader slots.

Step 1: Listen to the computer and look at the lights

To help determine if the problem is being caused by the computer, turn on the computer and listen to it. Look at the computer's lights. What do you notice?
  • If the computer is make a beeping sound when turned on, a card, cable, memory module, or processor inside the computer may have came loose. Go to Reseat loose internal components to check for loose components.
  • Do you hear the computer's fans spinning? If you do not hear noise from the fans and the power lights on the computer are not on, the problem is related to the computer, not the monitor. To continue troubleshooting a computer that does not start, select your operating system below:
  • If you can hear the computer's fan spin and see lights on the computer, the problem is probably caused by the video cable connection or the monitor. Continue to the next step.

Step 2: Connect the computer to another monitor

Connect another monitor to the computer to determine which device has the problem (the monitor or the computer). If you do not have an extra monitor, temporarily connect the computer to a friend's monitor for troubleshooting purposes.
After the monitor is connected, turn on the computer and the monitor. What happens?
  • If the newly attached monitor does not display anything, disconnect the cable and continue at Step 3: Inspect the video cable and video connectors for damage
  • If the newly attached monitor displays the first startup screen(s) but then goes black, there is a problem with Windows starting. Skip to Step 5: Change the display resolution .
  • If the new monitor works, the original monitor or its cables are faulty. Do the following:
    1. Replace the monitor power cable.
    2. Turn on the monitor. If the monitor displays an image, you are done. If the monitor remains blank, continue using these steps.
    3. Replace the video cable.
      Turn on the monitor. If the monitor displays an image, you are done. If the monitor remains blank, continue using these steps.
    4. If the monitor does not work after replacing the cables, replace or service the monitor.

Step 3: Inspect the video cable and video connectors for damage

Inspect the video cable and video connectors for damage. Check for sharp bends or breaks in the cable, or bent or broken pins at the connectors. With the monitor and computer off, try to straighten bent pins with a small metal tube, like the tip of an empty mechanical pencil or the tip of a retracted pen.
Figure 1: Video connector
If you had to straighten any pins, reconnect the monitor making sure that the video cable is firmly connected and then turn on the computer and monitor. If the display is still blank, continue to the next step.

Step 4: Reset and update the BIOS

You can use these steps even though you will not be able to see anything on the monitor.
In case an item was changed in the BIOS, such as the primary display device setting, use one of the following sections to reset the BIOS back to its default configuration:
  1. Turn on the computer and repeatedly press the F10 key for eight seconds.
  2. Press the Down arrow three times.
  3. Press the Enter key two times.
  4. Restart the computer.
  1. Turn on the computer and repeatedly press one of the following keyboard keys. Press the key about once every second for 5 seconds after turning the computer on.
    • For HP and Compaq computers that came with Windows 7 or Windows Vista, press F10.
    • For HP and Compaq computers that came with Windows XP, press F1.
    • For Compaq Presario desktop computers built prior to 2002, press F10.
  2. Wait another 5 seconds.
  3. Press the F5 key. This restores the default settings of the BIOS.
  4. Press the Enter key. This accepts the changes.
  5. Press the F10 key. This saves the changes.
  6. Press the Enter key. This saves the changes and exits from the BIOS.
  7. The monitor should display the first screens received from the computer (the logo screens). If not, find and download the latest BIOS update if one is available for your computer.
  8. If a BIOS update was not available or the monitor is still blank, continue to the next step.

Step 5: Reseat loose internal components

If the computer case was recently serviced or moved, a card, cable, memory module, or processor may have become loose. When this happens, the computer might make a beeping sound when turned on. Use the following steps to check for loose components:
WARNING:The edges of metal panels can cut skin. Be careful not to slide skin along any interior metal edge of the computer.
CAUTION:This product contains components that can be damaged by electrostatic discharge (ESD). To reduce the chance of ESD damage, work over a noncarpeted floor, use a static dissipative work surface (such as a conductive foam pad), and wear an ESD wrist strap connected to a grounded surface.
WARNING:The edges of metal panels can cut skin. Be careful not to slide skin along any interior metal edge of the computer.
  1. Unplug all cables except for the power. Write down each cable location if you do not already know where it connects.
  2. With the power cable removed press the Power button on the front of the computer for 5 seconds.
  3. Remove the screw(s) that retain the panel or cover from the rear of the computer.
  4. Slide the side panel off from the rear of the computer.
  5. Gently press down on the outside edges of cards and memory modules that are inserted into the motherboard to better seat them. Do not press too hard.
  6. Gently press down on the connectors of the flat ribbon cables to seat them.
  7. Replace the side panel and screw(s), reconnect the computer cables, and turn on the computer.
  8. If the monitor still displays a black screen, the video hardware may be faulty and needs to be replaced or serviced. If the monitor displays the first startup screen but does not display Windows, continue to the next step.

Step 6: Change the display resolution

This step will not work if you cannot view the first startup screens as noted in the previous section.
Use the following steps to change to a compatible display resolution and color depth setting from a standard graphics mode. For flat panel LCD monitors, set the display resolution to the monitor's native display resolution.
NOTE:Connect the computer to a working monitor to perform these steps.
NOTE:If you cannot select your monitor's native display resolution, then update the computer's video drivers and repeat this step.
  1. Turn on the computer and press the F8 key repeatedly when the first startup screen appears.
  2. Increase the display resolution as follows.

Step 7: Disable power settings in BIOS

If Windows was recently upgraded, Windows might be starting up into a Power Saving state and producing the blank screen before it loads. After Windows loads (about 2 minutes after turning on the computer), press the power button briefly or press the Suspend key on the keyboard to see if the computer comes out of a suspended state. If the computer opens into a suspended state every time the computer is started, use the following steps to disable Power Savings in the BIOS.
NOTE:Connect the computer to a working monitor to perform these steps.
  1. Turn on the computer and repeatedly press one of the following keyboard keys. Press the key about once every second for 5 seconds after turning the computer on.
    • For HP and Compaq computers that came with Windows 7 and Vista, press F10.
    • For HP and Compaq computers that came with Windows XP, press F1.
    • For Compaq Presario desktop computers built prior to 2002, press F10.
  2. In the Setup screen, press the Right Arrow key and select Power.
  3. Press the Down Arrow key to select and configure one of the following items depending on what appears on your screen:
    • Power Savings, APM, or Advanced Power Management - select Disabled and press the F10 key to save the settings and Exit.
    • APIC Interrupt Routing - If the computer is using Windows XP and this setting is disabled, select Enabled and press F10 to save the settings and exit. Let Windows restart and set your power preferences from within Windows.
      If Windows still does not appear or you are unable to use the power options in Windows, find and download the latest BIOS update if one is available for your computer.
      Reset the APIC Interrupt back to its previous setting if problems occur.
  1. Turn on the computer and repeatedly press F10. Press the key about once every second for 5 seconds after turning the computer on.
  2. In the BIOS Setup utility, press the Right Arrow key and select the Power tab.
  3. Press the Down Arrow key to select Hardware Power Management.
  4. Press the Right Arrow key to disable SATA Power Management.
  5. Press F10 to save the settings and exit.
NOTE:If you are still experiencing problems with an LCD flat panel display, there are more steps you can use to resolve your problem. Please refer to the HP support document Screen Is Blank after Starting the PC, or Power Adapter Connector Appears to be Missing (in English).

Step 8: Replace the video card or have the hardware serviced

If you have tried all of the steps in this document and are still having the issue, the hardware is probably faulty.
If the monitor does not work on another computer, the monitor may be defective. The monitor should be replaced or serviced. You can Contact HP (in English) to find support if your monitor is in warranty or an authorized service center to assist you if your monitor is out of warranty.
If the monitor works on another computer and the computer has a video card, try replacing the video card on the computer.
NOTE:Use these steps only if the computer has a video card. Many HP and Compaq desktop computers do not come with a video card.
  1. Remove all memory cards, USB flash drives, and CDs/DVDs from the computer, turn off the computer, and then open the computer case.
    NOTE: If you need product model specific graphics and instructions for opening the computer, search for a support article that pertains to your computer. Enter the computer's model number into the Product field at the top of this page and search for opening the case.
  2. Locate the video card.
  3. Disconnect any cables connected to the card and remove the video card.
    NOTE:Removing the video card can be difficult. If you need more information about replacing the card, do one of the following:If your computer has Windows XP or earlier, see the HP support document Installing or Replacing a Video Card .If your computer came with Windows 7 or Vista, enter the computer's model number into the Product field at the top of this page and search for Removing and Installing an Expansion Card.
  4. Install the new video card and connect the cables to the card.
  5. Plug in the power cable and turn on the computer.
    CAUTION: Keep any items away from the internal area of the computer to avoid damaging the computer.
Compaq Q2009 20 inch Diagonal Widescreen LCD Monitor

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