The notebook diagnostic utilities use the LEDs near the Num Lock and Caps Lock keys to blink a series of error codes ("blink codes"). At the end of the series the blinking stops. Until the error is resolved, the pattern of blinks will occur any time an attempt is made to start the computer.
The LED lights near the Caps Lock and Num Lock keys will blink if an error is detected during the startup process. The LEDs will blink a number of times in a sequence and then stop. The number of blinks in the sequence indicates what component caused an error when it was being tested during start up.
If the LEDs stop blinking and the computer does not start, you can press the Power button again to repeat the tests. After you count the number of blinks, use the chart to identify the error condition, and then see the corresponding section for that error condition below for troubleshooting steps.
LEDs blink 1 time CPU not functional
LEDs blink 2 times BIOS corruption failure
LEDs blink 3 times Memory Module error not functional
LEDs blink 4 times Graphics controller not functional
LEDs blink 5 times System board General system board failure
LEDs blink 6 times BIOS authentication failureCPU IS NOT FUNCTIONAL
The computer processor has stopped functioning properly (Blink code 1). Contact HP for assistance.BIOS corruption failure
If a BIOS corruption error occurs (Blink code 2), you may not even notice the blink codes, because as soon as the computer recognizes the error, it restarts, attempts to recover the BIOS, and then restarts again. You may notice an extra-long startup process as a result, and a message indicating that the BIOS has been recovered may display on startup. If this occurs, update the BIOS on the computer. For more information, see Updating the BIOS
.If the computer does not automatically recover the BIOS, manually perform a BIOS recovery by following these steps:
- Turn off the computer.
- Plug the notebook into power using the power adapter.
- While the computer is still off:
- Press and hold the Windows key and the B key at the same time, and then press and hold down the Power button on the notebook for one second.
- Release the Power button and the keys.
By following these steps the BIOS will reach the EFI partition in order to recover the BIOS to the last known good version of the BIOS from the hard drive.For information on how to restore the BIOS refer to the HP support document: HP Notebook PCs - Restoring the BIOS
.Memory Module error not functional
If you experience a memory failure (Blink code 3), follow the guide in the table below.
|If Using Original Memory||If New Memory Is Added|
Reseat the memory.
If reseating the memory does not resolve the problem, try replacing the memory with new memory.
Reseat the memory.
If you continue to experience this error code after reseating the memory, the problem may be with the memory itself. Take the new memory out of the computer, put the original memory back into the computer, and then retest it.
Reseating memory modules in a notebook If a memory module is loose or is not making good contact with the memory slot, the computer can fail to start. To reseat the memory module, take the memory module out of the memory slot, and then put it back into the slot to make a better connection so the computer can recognize the memory.The memory module compartment on most notebooks is located on the bottom of the case, however, on some models, the memory compartment is under the keyboard. See your User Guide for the exact location of memory modules on your notebook.Use the following steps to remove and reseat the memory modules:
Turn off the computer, and then disconnect the power cord.
Remove the cover to access the memory.
Figure 4: Removing the cover
Figure 5: Memory module cover (your cover may be different)
1 - Retention screws (2)2 - Direction to remove compartment cover
Remove all of the memory modules in the computer.
Figure 6: Removing the RAM
Reinsert all memory modules.Figure 7: Notch alignment and memory module insertion
1 - Notch alignment2 - Direction to insert the module3 - Direction to seat module
Graphics controller not functional
- Replace the cover, battery, and power cord.
- Turn on the computer.
- Perform any tests to verify that the computer can start up and run in the Windows operating system. If the computer fails to boot to the Windows desktop after the memory is reseated and the battery is installed, contact HP for support.
If you experience a graphics controller failure (Blink code 4), contact HP for assistance. Notebook general system board failure
A general system board failure (Blink code 5) is the failure of a component not covered by the other LED error codes. Contact HP for assistance.Notebook BIOS authentication failure
The BIOS authentication error (Blink code 6) is extremely rare. It is the result of a discrepancy between the BIOS and the hardware that is installed on the computer. This error occurs when the BIOS cannot authenticate signatures from the hardware on the system. The purpose of the BIOS authentication is to be sure that no one has tampered with the BIOS on the computer.If a BIOS authentication failure occurs, the computer automatically performs a BIOS recovery. If the computer does not automatically recover the BIOS, perform a BIOS recovery manually by pressing all four arrow keys at the same time to cause the BIOS to go to the EFI partition to find and recover the current BIOS. If a manual BIOS recovery is not successful, contact HP for assistance.