There are many reasons that a computer does not startup or boot into the Windows operating system, but most of them are easy to resolve.
If your computer will not startup or boot, you will most likely see some type of symptom to indicate the general area of the problem.
Troubleshooting a startup / no boot problem is a process based on identifying symptoms exhibited and performing corrective tasks. If one action does not resolve the problem, identify the next symptom and continue the corrective actions.
Symptom: LED lights do not glow
The notebook does not start, none of the LEDs glow, and there is no other indications of power to the computer when the notebook power button is pressed. Other indicators of a no power condition include: no blinking lights, no beeping sounds, no audible sounds such as fan noise or the hard drive spinning up.
The cause of this 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.
Before starting to troubleshoot the black screen error, you should first follow the instructions in
Preparing to Diagnose the Computer
.
If the computer starts up normally to the Windows desktop after performing any of these processes, no further action is needed.
Once you have verified that power is available but the computer does not startup or boot into Windows, see the table of symptoms and read the suggested document.
Identify the Startup and Boot Sequence and Problem Symptoms
| Startup and Boot Sequence | Problem Symptom | Corrective Actions |
|---|
| 1. When you press the Power button to start the boot process, the hardware verifies that there is sufficient electrical power to activate the hardware. | If there is no power, or insufficient power, the LED light on the AC adapter or power connector, and the LEDs on the keyboard do not glow. Also, there is no sound of the fan or hard drive spinning, and the screen remains blank.
The fan sounds and LEDs may be on briefly and then stop. | If this is your symptom, use this document to troubleshoot the issue.
|
| 2. The BIOS queries various hardware components used for the startup boot process. | If a component has certain communication or physical failures, the screen remains blank, however the LED lights blink in a sequence to indicate a component error.
On older models the computer beeps to indicate the error. |
Step-by-Step
Troubleshooting LED Lights Blinking or PC Beeping During Startup or Boot |
3. The BIOS loads the basic input (keyboard) and output (advanced LEDs / display screen / boot drives) devices into memory
The HP / Compaq logo appears briefly on a black screen. | If the internal checks find an error, the boot process stops and a black screen – with an error message – displays.
|
Step-by-Step
Troubleshooting Black Screen Error Messages that May Display During Startup or Boot |
| 4. The BIOS loads the Windows operating system and starts the services that allow low-level control of all of the background operations. | If the internal checks find an error, the boot process stops and a blue screen – with an error message – displays.
|
Step-by-Step
Troubleshooting Blue Screen Error Messages that May Display During Startup or Boot |
| 5. Control is transferred to the Windows loader to initiate the display of the advanced settings in the Windows environment. The Windows logo displays during this step. | If the Windows self-checks find an error, the boot process stops and a screen with the Windows logo and an error message – displays.
The Windows logo may appear, or it may appear and then go off, or the logo may flash and the computer will attempt to restart. |
Step-by-Step
Troubleshooting Error Messages with the Windows logo that May Display During Startup or Boot |
Preparing to Diagnose the Computer
Before you can troubleshoot a startup no boot problem, you must be able to identify the problem. Perform the following actions to prepare the computer for troubleshooting a startup problem.
Disconnect all peripheral devices
. Many startup / no boot issues can be resolved by disconnecting any USB, PC card, express card, eSata, Firewire, or similar devices and other connected hardware—such as a printer, scanner, camera, keyboard, mouse, port replicator, or docking station. You should also remove any CD or DVDs from the optical disc drive and any media from the card reader.
Perform a Hard Reset
. Many startup / no boot issues can be resolved by resetting the power management logic.
To perform a Hard Reset, unplug the AC power adapter and remove the battery, and then press and hold down the Power
button for about 6 seconds. This will drain any residual charge in the capacitors and reset the power management controls to their default condition.
You can now connect the AC adapter to the notebook and plug the adapter's power cord directly into a functioning electrical outlet and begin diagnosing the startup / no boot problems.
Verify that the LEDs glow
There must be adequate power from the battery or the AC power adapter to start the computer. You can look at the LEDs to quickly verify that power is available to the computer. LEDs are usually located near the power switch and the wireless switch. On newer models of notebook PCs, there is an LED or indicator light around the power socket on the notebook. See the User Guide for the exact location of LEDs on your computer.
Typical Locations of LEDsThe LEDs near the keyboard and the power socket indicator light should turn on, or glow, when the AC adapter is connected.
If the light on the power socket does not
glow then the problem is most likely related to the AC adapter or the electrical source in your home or office. Go to Test the AC adapter
.
| Figure 1: LEDs  |
Figure 2: Power indicator light.  |
 |
Note: Power socket LEDs are not available on all computers.
Test the AC power adapter in a different AC outlet
If none of the LEDs glow when the AC adapter is connected to the computer, verify that the AC outlet is functioning. You can do this by connecting a lamp to the outlet and see if it lights. If not, try using a different AC outlet that you know if functioning. If the outlet is good, continue with testing the AC power supply.
Test the AC power supply
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.
| NOTE: | Because the following actions are designed to test the AC power supply, the battery should be removed from the notebook until all the tests are completed. |
Verify the AC adapter is the correct adapter for the computer.
Every notebook has specific power requirements, and uses a connector of a given size. If the adapter does not provide enough power or the plug does not connect firmly, the computer will not operate properly.
Disconnect the AC adapter from the notebook.
Remove the battery.
Disconnect all external devices such as a printer, docking station, or USB device, and remove all CDs/DVDs from the computer.
Press and hold the Power
button for several seconds, with all power sources removed. This action, called a "Hard Reset", drains residual power from the system and may correct many problems.
Connect the AC adapter directly into a functioning wall outlet and connect the adapter to the computer.
Press the Power
button to start the notebook PC.
Examine the adapter and power cord for physical damage
Check both the cord from the AC outlet to the adapter, and the round cord from the adapter to the computer, for physical damage such as fraying or cuts. Also examine the power adapter for signs of damage or overheating.
Check the power socket on the computer to ensure that the pin inside the socket is not bent or broken. If the pin is broken, contact HP for technical assistance.
If the cords, connectors, or the power adapter are damaged, contact HP to order a new AC power adapter.
Start computer using a different AC adapter
If you have access to a different AC adapter or power pack that is designed for the computer, connect it to the notebook and try to start the computer.
| CAUTION: | Use an adapter that is designed for the computer. Using a power adapter that does not meet the power requirements or has the wrong type of connector may damage the computer. |
If the computer starts up and operates properly with the replacement power pack, 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 replacement power pack, there may be a problem with the system board, contact HP for technical assistance.
Check that the lid switch moves freely
Some notebooks have an external switch, located near the hinge, which turns off the monitor and can be programmed to shut down the computer when the lid is closed. Press and release this switch to verify it is not stuck in the down position.
Charge the battery with the computer turned off
If the LED glows for a short time but then goes out when you press the power button, your battery may be discharged and is not getting a sufficient charge. This may be resolved by removing and reseating the battery, and then allowing the battery to charge for at least 30 minutes.
Slide and hold the battery release latch to the unlock position.
Use your finger to lift the battery up and out.
Before replacing the battery, connect the AC adapter and press the Power
button to start the notebook.
Once you have verified that the notebook will start, turn off the notebook, disconnect the AC adapter.
Replace the battery.
Reconnect the AC adapter to the notebook.
Verify that the power LED, located near the power icon (displayed as a lightening bolt on most PCs)
, is glowing to indicate the battery is charging.
Allow the battery to charge for at least 30 minutes.
When the battery is charged, disconnect the AC adapter and start the computer using the battery power only.
What you can do if the computer still does not startup or boot properly
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.
What to do when the computer starts normally
After you have completed the troubleshooting process and your computer has booted normally to the Windows operating system, you should update your Windows operating system and software, your HP software and drivers, and then run the HP diagnostic tools to ensure that all of the computer hardware and software is functioning correctly.
