Computer Starts but Monitor Remains Blank

Before you begin troubleshooting a blank monitor

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 USB flash drives and memory cards from card reader slots.

Step 1: Check the power

Disconnect the video cable from the monitor and make sure the monitor power cable is plugged into a power outlet.

With the monitor plugged in, press the power button on the monitor. There is a power indicator light located on the monitor case.

If the power light comes on, the monitor has power, skip to Check for fan noises, beeps, and power lights.
If power light remains off when you press the power button, either the monitor is not receiving power or the monitor is defective. Check all the following items before attempting to service or replace the monitor:
- Make sure the power outlet has power and the power outlet matches the power rating for the monitor.
- Connect the monitor to a different power outlet.
- Try a different power cord.

If the light comes on, the monitor has power. Continue to the next step.

Step 2: Check for fan noises, beeps, and power lights

To help determine whether the problem is caused by the computer or the monitor, turn on the computer, listen for sounds, and look at the lights.

If the computer makes a beeping sound when turned on, a card, cable, memory module, or processor inside the computer might have come loose. Go to Reseat loose internal components to check for loose components.
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 troubleshoot a computer that does not start, see Computer Does Not Start.
If you can hear the computer fan spinning 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 3: Reset the monitor

At first setup, or under certain signal conditions, the monitor might not be able to switch to a new display resolution. Do not shut down or restart the computer. Instead, reset your monitor. If you need instructions for resetting your monitor, search the HP support website. Go to HP Customer Support, and follow the instructions to find your product.

You should see the image from the computer on the screen. If not, continue to the next step.

Step 4: Check for error messages on the monitor

Use the following steps to see if a built-in on-screen message is displayed.

Connect the video cable and turn on the computer.
Turn on the monitor and wait about ten seconds while the computer starts.
While the computer is starting, disconnect the video cable.
- If a message is displayed, the monitor panel is working and the problem is related to the video signal. For further troubleshooting steps, see, Flat Panel Monitor Displays Message about No Signal, Signal out of Range, Sleep, or Power Save.
- If the monitor remains blank, turn off the computer and continue troubleshooting.
- Some monitors do not have on-screen messages but instead use the lights to indicate no signal. When you disconnect the cable, instead of an on-screen message, the light turns amber, indicating that the monitor lost signal and is working properly, but is out of range, or not receiving the signal.

Step 5: Check cable connections

If you see the initial HP logo screen but later lose the picture, go to Connect the computer to another monitor.

Otherwise, check the video cable connection on the back of the computer and on the monitor. Make sure that it is connected properly and the connecting screws are tight. Turn the monitor off and then back on again (while the computer is on) to see if an image is displayed.

Make sure that you have the monitor power adapter cord plugged into the power connector.

After you have reconnected the power cord, turn on the monitor (while the computer is on) to see if an image is displayed. If there is still no image, continue to the next step.

Step 6: Connect the computer to another monitor

Connect the computer to another monitor 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 another monitor for troubleshooting purposes.

After the monitor is connected, turn on the computer and the monitor.

If the newly attached monitor does not display anything, disconnect the cable and continue to the step to Inspect the video cable and video connectors for damage.
If the newly attached monitor displays initial startup screen(s) but then goes black, there is a problem with Windows starting.
If the new monitor works, the original monitor or its cables are faulty. Try connecting the monitor with a different video cable. If the monitor still does not work, replace the monitor power cable. Replace or service the monitor if it still does not turn on.