I recently bought a Lenovo T440s and I've been experiencing a strange screen flicker issue. At least, I think "flicker" is the correct word to describe it.
My problem is not like the one described here (My Laptop Screen keeps flickering). The entire screen does not flicker or go black. Rather, a portion of the screen near the middle will periodically flicker a bit. It looks something like a CRT monitor would look like when certain refresh rates are used. It's especially noticeable if you're viewing any type of pattern on the screen. I want to stress that this only happens in a sub-portion of the screen near the center. It will happen for a while and then go away.
I haven't been able to capture a video of it - I'll try to and update my post. I will say that it seems to happen when my laptop is under heavy use and it warm to touch.
Update: I ran 3D Mark and Prime 95 for a while and neither were able to produce the flicker issue.
I don't think it's an OS/driver issue because I can see it when my computer is booting up and when I'm in the BIOS (I'm running Windows 8.1).
If anyone has any ideas as to how to debug or root cause this I would appreciate it.