Many startup errors and other problems can be resolved by decreasing the amount of power stored in hardware components. Decreasing stored power is sometimes referred to as a "Hard Reset". Use the following steps to perform a hard reset on a computer:
If Windows is open, click Start and then Shutdown.
If Windows is not open and the computer has power, press and hold the power button on the computer until the computer shuts off.
With the power off, disconnect the power cord from the back of the computer.
With the power off and the power cord disconnected, press the power button on the computer for 5 seconds. The power light indicator on or near the power button might turn on briefly but then go out.
Reconnect the power cord and turn on the power.
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.