This
document pertains to HP Notebook PCs with the HP Unified Extensible Firmware
Interface (UEFI) beginning in late-2008.
On
startup, you may see a blank screen. If the diagnostic utilities detect a
specific problem with hardware components, the fan turns on, but the screen
remains blank. To help identify the cause of the problem, various LED lights on
the keyboard blink a series of codes.
The
diagnostic utilities use the LEDs near the Num Lock or Caps Lock
keys to blink a series of error codes. At the end of the series the blinking
stops. The pattern of blinks will occur any time you attempt to start the
computer until the error is resolved.
Battery
power LED blinks
The
Battery power LED indicates the condition of the power supply. When starting
the computer, or when the computer is in operation, use the chart to identify
the power condition.
Battery Power LED
|
Component Tested
|
Error Condition
|
Battery
power LED off, and Caps Lock/Num Lock off
|
Battery
or AC Adapter
|
AC
adapter not connected or failure
Battery low charge or failure
|
Battery
power LED blinking
|
Battery
|
Insufficient
charge on the battery
|
|
|
When
new computer is used for first time, the white LED light for the AC power
connector blinks.
|
Battery
is still in "Shipping Mode", the light continues to blink even when
AC power is connected.
To resolve, turn off notebook, connect AC power and allow battery to charge
for at least 30 minutes, then start computer.
|
LEDs
near Caps Lock and Number Lock keys blink when starting notebook
The
LED lights near the Caps Lock and Num Lock keys will blink if an error is
detected during the start up 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. Count the number of blinks, and use the chart
to identify the error condition.
Knowing
the number of blinks is helpful when you contact an HP support agent for
technical help.
Caps Lock/Num Lock LED
|
Component Tested
|
Error Condition
|
LEDs
blink 1 time
|
CPU
|
CPU
not functional
|
LEDs
blink 2 times
|
BIOS
|
BIOS
corruption failure
|
LEDs
blink 3 times
|
Memory
|
Module
error not functional
|
LEDs
blink 4 times
|
Graphics
|
Graphics
controller not functional
|
LEDs
blink 5 times
|
System
board
|
General
system board failure
|
LEDs
blink 6 times
|
BIOS
|
BIOS
authentication failure
|
Error code explanations
The
sections below provide some common explanations for each error code listed in
the table above.
When
the computer is on battery power only and the AC adapter is disconnected, if
the Battery Power and Caps Lock / Number Lock LEDs do not glow, there is either
a very low change or no charge in the battery. Connect the AC power adapter,
verify that the battery power LED glows, allow the battery to charge for 15 -
30 minutes and then attempt to start the computer. If it starts, run the battery
test and calibrate the battery. If it does not start, if possible, connect a
replacement battery to verify that the battery is the problem.
If
the computer does not start after charging the battery, remove the battery and
connect the AC power supply. Verify that the battery power LED glows, and then
attempt to start the computer. If the LED still does not glow, either the AC
adapter has failed, or there is a bad connection between the adapter and the
system board. If possible, connect a different AC power adapter to verify that
the adapter is the problem, or contact HP for support which may require a
service event.
Insufficient
charge on the battery
If
the battery light LED (which looks like a lightning bolt )
flashes, the battery has insufficient charge to start the computer. To resolve
this error, try the following solutions.
- Connect the notebook PC to AC power and attempt to
start the computer again.
- Check the AC adapter to confirm that all of the plugs
are securely seated.
- Determine if the power LED on the AC adapter is lit
(if available) to verify that the computer is receiving AC power from the
wall outlet.
- If the computer operates on AC power correctly, charge
the battery for thirty minutes to one hour and then restart the computer.
NOTE:Charging
the battery for this length of time is called "trickle charging".
Trickle charging is a continuous constant-current charge at a low rate, which
recharges the battery slowly when it is in a deep discharge state. Deep
discharge occurs when a battery is left unused for extended periods of time.
CPU
not functional
The
computer processor (Blink code 1) has stopped functioning properly. 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, refer to the HP
Notebook PCs - Locate and Install Updated BIOS, Drivers, and Software .
support
document.
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.
|
If
you do not feel comfortable reseating the memory yourself, take the computer to
a computer retailer and ask them to reseat it for you.
NOTE:Some
memory module errors may allow the computer to start but will then cause the
computer to restart and display a blinking error code.
Graphics
controller not functional
If
you experience a graphics controller failure (Blink code 4), contact HP for
assistance.
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.
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,
manually perform a BIOS recovery. To manually perform a BIOS recovery, press
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.
