HP answers at link.

by R. Proffitt Moderator - 12/19/12 4:28 PM

In Reply to: Help with my hp dv7 by scoutsout2k6

http://h30434.www3.hp.com/t5/Notebook-Hardware-e-g-Windows-8/Blinking-caps-and-num-lock-lights/td-p/29560

For a test, remove the AC power, then the battery then press and hold the power button for 60 seconds. Release and apply only the AC power. We want to find out if the power adapter is working at this step.

Try to power up. What happens?

To add the battery, turn off, remove AC then install the battery.
Bob