Flickering Monitor

[yogainium]

Hello HP community,

I bought two HP 23.8-inch FHD IPS Monitor several months ago and one of them starting having a flicker with black horizontal lines (see image attached).

I've tried a lot of things to fix it:
1) Change HDMI cable
2) Change power cable
3) Change HDMI port
4) Change power wall outlet
5) Press the "Shutdown" monitor's button for 1 minute while unplugged from the power

But none of them worked.

I also tried changing the refresh rate (initially at 60 Hz) down to 50 Hz and instead of flickering the black lines stay. 

The flickering happens even while the monitor has no hdmi cables plugged in.  The other monitor works just (even when changing HDMI cables and power cables). I am using a Dell XPS 13 and the laptop screen is fine as well.

Is there any way to fix it without having to bring it somewhere?

Thanks.

[Ondrej94]

Can you try different cables like VGA / Display port?

Are you using docking station for your laptop?

Did you tried to change resolution?
Can you plug in monitor to different laptop / PC?

[yogainium]

I am not using a docking station for my laptop.

The flickering occurs with no laptop plugged in.

Changing the resolution did nothing.

Plugging the monitor into a different laptop did nothing.

Using DisplayPort compared to HDMI did nothing.

[Ondrej94]

Well, I think you should use your warranty and send display back to HP