When the external AC power supply is unplugged from a notebook, the LCD display will dim to conserve on battery power. During times of heavy battery power operation; such as during the startup or boot process, the display may be very dim or barely readable.
If the display remains dim when the notebook is operating on the Windows desktop, follow the steps below to resolve problems with display brightness
Restart the notebook with AC power
Follow the steps below to determine if the dim display is due to a hardware failure:
If the display is still dim after restarting with the AC adapter connected, try changing the LCD brightness.
Adjust the LCD brightness using the function keys
From the Windows desktop, hold the fn key and press the f7 key to increase or the f8 key to decrease the brightness of the display. If using the function keys does not resolve the problem and you have a Lid Actuator on your particular model, check the movement of the Lid Actuator switch to determine that it moves freely and is not stuck.
The key numbers ( f7 or f8 ) may vary depending on the notebook PC; however, the images on the keys should be familiar.
Check the movement of the Lid Actuator switch
The Lid Actuator switch is available on some models. It is a small button or switch located above the keyboard near the hinge for the LCD. Pressing this switch when the computer is on may turn the notebook display off, or it may cause the notebook to enter a different power state.
Press the switch two to three times while observing the display. If the display does not return to normal brightness when the switch is released, the switch may be sticking and need to be repaired. Contact HP service and support for further assistance.
If the display turns off when the switch is pressed, the power management function may be set to hibernate or turn off when the lid is closed.
Install updated BIOS and drivers
To resolve certain hardware and software issues, use HP Health Check to automatically search the HP web site for an updated BIOS as well as any updated software and drivers.
To launch HP Health Check, follow the steps below.
Connect the AC adapter to the notebook and a working electrical outlet.
Power down the notebook PC by pressing and holding the power button for 5 seconds.
Press the power button again to start the computer.
You have now installed the available BIOS, software, and driver updates for your particular computer model.
Contact HP service and support
If the display remains dim after doing the troubleshooting steps listed in this document, contact HP service and support for further assistance.
Click Start , type health into the search field, and then select HP Health Check from the list.
HP Health Check displays a list of available BIOS, software, and driver updates for your particular model.
Click the description link for any BIOS, software, or driver updates, and then follow the on-screen instructions. You can only install one update at a time.
Repeat steps 1 and 2 above for all updates that you want to install.