Thin (1-px) gray vertical line on laptop screen

[thomaswp]

I have a Lenovo Y50-70 non-touch laptop, about 2.5 years old. Recently, I've noticed a vertical, gray, 1-pixel-wide line near the left side of the screen. The line is present before boot (e.g. on the BIOS screen), so I know it's a hardware issue. The line is most visible against highly-saturated colors (e.g. green, orange), and almost invisible against a black or white background. Here's a picture, though it's a bit hard to see, so I've drawn a yellow border around it:

I'm trying to diagnose the issue, and my understanding is it is likely either the screen itself or the cable connector. So far I haven't managed to find this exact issue in the forums. So my questions are:

1) What do you think the issue is? Cable, screen, or something else?
2) If it is the cable (my hope), is this cable the right part to be replacing?

I really appreciate any help.

 

[ss202sl]

You won't know if it's the screen or the cable without replacing one, and the cable is probably much cheaper than the screen. I'm not sure it would be the cable. I'm guessing it's the screen.
Does it show up on an external monitor?

 

[thomaswp]

You won't know if it's the screen or the cable without replacing one, and the cable is probably much cheaper than the screen. I'm not sure it would be the cable. I'm guessing it's the screen.
Does it show up on an external monitor?

No, everything works just fine with an external monitor. Thanks for the input - I figured I'd try the connector first, but if someone has a good reason to expect the screen itself, I may skip that step. I have a warranty, but I'd very much like to avoid sending in the laptop for 2 weeks.