This app was mentioned in 10 comments, with an average of 1.60 upvotes
On the playstore search "Screen checker" The one I use is this one Just tap the screen to cycle through the modes and you'll see.
have you tried using the screen test app? if it is there it should make it easier to see with the solid color backgrounds
https://play.google.com/store/apps/details?id=com.yota.screentest&hl=en
Noticed the horizontal lines on my 1.5 year old Nokia 5.1 Plus the other day. It went away for a day or two, then its now reappeared.
The lines are not visable during most of the tests via
https://play.google.com/store/apps/details?id=com.yota.screentest
Also tried a screenshot and the image it self is fine when viewed on another device, so the problem seems to be hardware based.
Any ideas?
Honestly just looking at it should tell you. If you go into a dark area and pull up a picture of black using this app, 1 of 2 things should happen:
I used this:
https://play.google.com/store/apps/details?id=com.yota.screentest&hl=en
The mid-grey shows the issue most clearly.
https://play.google.com/store/apps/details?id=com.yota.screentest
Use this to test.
I wanted to see if I had it on my screen so I checked with this program
https://play.google.com/store/apps/details?id=com.yota.screentest
pretty handy thing.
Link me: Screen Test.
I used this to see how black it really was, and it's crazy.