All of the buttons are blinking

[AAAH]

All of the lights that it has is blinking

1. Wireless button/light
2. Wi-Fi Direct button/status light
3. Ink Alert light
4. Resume button/light
5. Information button/light
6. HP e-Print button/light
7. Power button/light

Screen blinks an 

1. "E"
2. Error icon
3. Paper Error icon
4. Wi-Fi Direct icon
5. Wireless icon
6. Wireless Attention icon 
7. Signal Bars icon
8. And an Envelope sign with an ink droplet on its top left corner.

It also appears offline in my computer.

[sandytechy20 · Accepted solution]

@AAAH 

Welcome to the HP support community.

I understand that the light on the printer is blinking, I am glad to assist you.

Perform a power reset , Reset the printer to recover from printer errors or failures.

1. Turn on the printer, if it is not already on.
2. Wait until the printer is idle and silent before you continue.
3. With the printer turned on, disconnect the power cord from the rear of the printer.
4. Wait at least 30 seconds.
5. Plug back the power cable straight to a wall outlet and printer without any surge protector.
6. Turn on the printer.

Refer to this HP document for further assistance:- Click here

Keep me posted.

If this helps, please mark the public post as an accepted solution so that it benefits several others.

Cheers.

[AAAH]

I did this a couple of times and it didn't work; but I guess that I should've kept it unplugged for longer, because I disconnected the printer for the whole night and the next day it was working again. 

Thanks for the help! 🙂