Inspiron 7490, Display Problem

I'm having the same issue with regards to the jerky sideways movement on my Inspiron 7490.  When I first purchased the laptop and it was still in warranty, I reported the problem to Dell Support who seemed to think it was a screen issue.  So they sent out an engineer who came and replaced the screen.

It seemed ok after the screen change, but as I don't use the laptop very often, I didn't pick up that the issue had not been resolved.

I've read the posts above and I will try connecting an external display to see if the same thing happens.  But as regards reseating the RAM modules, I believe the RAM on these laptop models are soldered to the motherboard.