Display screen black on HP Spectre x360

[ShankarIndia]

I have an 18-month-old HP Spectre x360 Convertible 15-eb0xxx. Couple of months ago, once there was a flicker on the screen. A permanent horizontal black bar appeared on the bottom of the screen, just above the taskbar (width of taskbar) and the taskbar got half-hidden within the black bar. It has been permanent since then, and no setting change could clear it off. I have tried to update all drivers, still it persists. A couple of days later, the display screen started to show stripes. The stripes would appear if the laptop turns active after being in standby mode for some time. Then the stripes would fade away slowly and the display would become normal. Again if the laptop is idle and goes into standby and comes back on, the problem would repeat and become normal after some usage. This is happening consistently. Now since yesterday, the display has gone completely black. However, if I connect the laptop to an external monitor, it works and display is seen on the monitor, just that there is no display on the laptop screen itself. Rest of the functions, keyboard, buttons, audio, webcam etc.. just work fine. 

I searched the forums seems like it has been a problem with this model for other users as well. Can you please suggest how can I get it fixed ?