Your num lock and cap lock are blinking. It indicate a BIOS fault.
Count how many times they blink. They should blink a few times, pause, then repeat the blinks sequence.
Next, go to https://support.hp.com/us-en/document/c01732674
It should be in the manual.
Blink once, pause, repeat (slow blink rate): CPU fault. Professional needed.
Blink twice, pause, repeat : BIOS corruption.
Blink 3x, pause... : Memory not recognized. Re-seat memory modules.
Blink 4x pause... : Graphic card fault. Professional needed.
Blink 5x, pause... :General system board failure. Professional needed.
Blink 6x, pause... : BIOS authentication failure.
The page show the procedure to perform when you can do it yourself. (cases 2,3 and 6)