Hp Elitebook 8570w Bios Password Reset [best]
You likely shorted power to ground for too long. Disconnect the AC adapter and main battery. Hold the power button for 30 seconds. Reconnect only the AC adapter. The motherboard should recover. If not, you may have blown a fuse.
Because the password is stored in Secure NVRAM within the KBC (Keyboard Controller) which has its own power rail or non-volatile flash. The CMOS battery only keeps the real-time clock running. hp elitebook 8570w bios password reset