Hi @thenameless86
Try removing the main battery from the laptop and then ''press and hold the laptop's Power button for a full 30 seconds'' and then release it.
Reinstall the main battery, reassemble the laptop, connect the charger, allow the battery to fully charge and then try turning it on.
Here's the [http://h10032.www1.hp.com/ctg/Manual/c05541747.pdf|maintenance and service guide] for the laptop. Go to p.27 to view the procedure to remove the battery