My name is*****'m a certified computer professional with 15 years of experience. It would be my pleasure to assist you with this.
This is often a sign of a hardware problem, meaning possibly the motherboard, the memory, etc. However, it could also be as simple as having a usb drive plugged in that the computer is trying to boot from. Let's begin by unplugging any usb devices (other than mouse and keyboard. Try to boot. If it still fails to boot, giving you the blinking lights, try removing the battery, and power cord, waiting a few minutes and trying to start up with only the power cord, not the battery. Please give this a try and let me know if it helps.
If those simple troubleshooting steps do not resolve the issue, here's a link to an HP site that may help you. http://support.hp.com/us-en/document/c01732674. If my answer has been helpful, please be kind and take a moment to rate me so I will be receive credit for my answer. If you need more help, please let me know so I can continue working with you or refer you to another expert. Your complete satisfaction is my goal!
You're welcome. I'm glad that you were able to find a solution. Have a great weekend!