HP Pavilion Notebook PCs support
Troubleshooting No LED Lights Glow During Startup or Boot
There are many reasons that a computer does not startup or boot into the Windows operating system. If your computer will not start or boot, you will see or hear symptom to indicate the general area of the problem. If you are not sure what the problem is, see Overview of How to Troubleshoot Problems When a Computer Does Not Start Up or Boot Properly .
Startup Symptom: LED lights do not glow, display is black, computer does not start
Use this document if the notebook does not start, none of the LEDs glow, there are no beeping sounds, no operating sounds such as fan noise or the hard drive spinning, and there are no other indications of power to the computer when the notebook power button is pressed.
The cause of this no power problem may be a failed AC adapter or power cord, a discharged or damaged battery, or a failed notebook system board component. Damaged components may require an HP certified repair. You can use this document to identify the cause of the startup no boot problem.
DO THIS FIRST - Perform a hard reset
If a PC suddenly fails to boot properly, you should perform a hard reset as the first procedure.
- Disconnect all peripheral devices and remove all USB devices and media cards. You want to test the computer not the accessories!
- Disconnect the AC power adapter, remove the battery, and then press and hold the power button for at least 15 seconds.
- Reconnect the AC power adapter (but do not connect the battery), Press the Power button, Look for glowing LEDs near caps lock and num lock keys, and Listen for sounds of a disk drive and fan turning.
|If the LEDs glow but the computer does not start, see
Troubleshooting Black Screen Displays with No Error Messages During Startup or Boot
If no LEDs glow, power is not being applied to the computer.
Figure 1: Typical Location of LEDs
The existence and location of LEDs is different on all computers.
Figure 2: Power indicator light.
When the AC adapter is connected, the power LED, located near the power icon (displayed as a lightening bolt on most PCs) , will glow to indicate the battery is charging. See the User Guide for the exact location of LEDs on your computer. Every notebook has specific power requirements. If the adapter does not provide enough power or the power plug does not connect firmly, the computer will not operate properly.
Common actions to resolve no power issues
If the computer does not start, the LED lights do not glow, and the display is black, you can perform one or more of the following actions to resolve the no power issue.
If the cords, connectors, or the power adapter are damaged, contact HP to order a new AC power adapter.
If none of the LEDs glow when the AC adapter is connected to the computer, follow the steps below to determine whether the problem is related to the AC adapter or may indicate a problem with system board. The battery should be removed from the notebook because the following actions are designed to test the AC power supply.
Do one or more of the following actions, then press the Power button and look for glowing LEDs or listen for sound of a fan spinning.
- Connect the AC adapter directly into a functioning wall outlet and connect the AC adapter to the computer.
- Verify the connector is firmly seated in the notebook.
- If you have access to a different AC power adapter that is designed for the computer, connect it to the notebook, and try to start the computer.
- If the computer starts up and operates properly with the replacement AC adapter, you have identified the source of the problem. Contact HP to order a new AC power adapter.
- If the LEDs do not glow and computer does not start using a known good AC power adapter, there may be a problem with the system board, contact HP for technical assistance.
If the LEDs do not glow, continue with the following actions to start the computer on battery power only.
If a battery is defective and does not accept a full charge from an AC adapter, it may prevent the computer from booting on battery power only. Also, if the AC adapter is defective, it may not charge the battery properly. To verify battery power available for the PC; with the computer turned off, connect the AC power adapter and allow the battery to charge for 30 minutes or more. Then, assuming the battery is charged, disconnect the power adapter and press the power button.
- If the computer still does not start and you have access to a battery from another identical computer, try using a different, fully-charged battery to repeat this test. Then, if the computer starts up and operates properly with the replacement battery, you have identified the source of the problem.
Contact HP to order a new battery.
Some notebooks have an external switch, located near the hinge. This switch turns off the monitor when the lid is closed. It can also be programmed to shut down the computer when the lid is closed. To test the lid switch, open and close the lid several times, or press and release the switch to verify it is not stuck in the down position.
When you have completed the troubleshooting steps covered in this document, there should be power available to computer. When you press the power button, the LEDs should glow, and you should hear the sounds of the fan and the hard drive spinning.
- If the battery does not accept the charge, or the notebook does not turn on without the AC adapter, contact HP to order a replacement battery.
- If the LEDs do not glow, and there are no other indicators of power being available to the computer, contact HP for technical assistance in troubleshooting a potential problem with the AC power connection or the system board.
- If the LEDs blink, or the computer beeps, but it does not start, go to HP Notebook PCs - Troubleshooting LED Blink Codes or Beep Codes During Startup or Boot .
- If the LEDs glow but the computer does not start on either battery or AC power, go to Troubleshooting Black Screen Displays with No Error Messages During Startup or Boot .
After you have completed the troubleshooting process and your computer has booted normally into the Windows operating system, you should:
- Run HP Assistant to update HP software and drivers.
- Run Windows Update to update operating system and software.
- Run anti-virus program to remove any virus.
For detailed information on this topic, see HP Notebook PCs - Update Your Computer After Troubleshooting a Problem .
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