Hi @momdad_4 ,
Check if there is a pattern to the blinks, rather than it being a continuous blink.
If there is or even if you're not sure, then here is a link to the [https://support.hp.com/au-en/document/c01732674#AbT2|LED error codes] for HP notebooks.
Scroll to ''BIOS light flashing error codes for computers released between 2011 and January 2015'' and click on the '''+''' symbol checkbox to expand the list.
Check if any of the "codes" are relevant.
Another thing to try is a power refresh.
Disconnect the charger from the laptop, (if connected), then remove the battery from the laptop, (using the ifixit [guide|83612] guide if necessary). Then press and hold the Power button on the laptop for 30 seconds to drain any residual power from the laptop.
Reconnect the charger to the laptop, (leave the battery out at this stage). Switch on the charger and turn on the laptop.
If it starts OK, allow it to boot all the way to the Windows desktop. Allow the HDD activity to settle down then shutdown the laptop in the normal manner.
Once it has shutdown completely, switch off and disconnect the charger, reinsert the battery, reconnect the charger and switch it on.
Turn on the laptop. If it starts, allow it to boot all the way to the Windows desktop. Once there, check the charge status of the battery. If it is charging, allow it to fully charge before disconnecting the charger.