The blinking caps light are an indication to the fault
See this hp/compaq website
https://support.hp.com/us-en/document/c01732674
Depending on the age of the laptop click on the + next to it
"BIOS flashing light error codes for computers released after April 2015"
"BIOS flashing light error codes for computers released between 2011 and January 2015"
Let us know what the light combination is
You could also try this
1. Remove the battery and charger
2. Hold down the power button for approx 30 seconds( this releases static electric in the capacitors)
3. Plug charger and battery back in and see if it worked