Windows 10: Laptop blinking lights from the caption key button and from the left side when it's not...

Hey Microsoft Team, listen I've got a problem on my laptop. When I power on my laptop the screen is black and the blinking lights from the side and from the caption key button, I tried to hard reset but didn't work at all. I was just charging my laptop and then that happened, my cousin's saying that my laptop that is sleeping like I didn't turn on sleep mode. Can you help me please?By,Jojo Raymund Servillon

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Press the Start button, blue power light blinks once, accessory lights blink once then nothing

I have a HP Elitebook 8740W running Win 10 Pro. When I press the start button the power light on the front of the laptop comes on for 2 seconds, then the accessory lights across the top of the keyboard blinks once, then nothing happens. The screen is blank.
If I hold the Start button down, the power light stays on for about 9 seconds then the accessory lights blink and then the screen is blank.

I have removed the battery and power wire, then held down the Start button for 30 seconds. Put the battery back in and the power plug. No change is anything.

The power light does not come on when the laptop is plugged in.

Any ideas on what to do now.

 

Why is the power button blinking light

The power button on my laptop keeps blinking and I'm getting no power however I haven't plugged into the charger and it is indicating that it is charged and the power light on the other side of the laptop is also on indicating that there should be power but Getting atype of home screen or anything like that please help

 

Blinking light

MODEL Dell 3521. Light blinking. second from left