Issue for screen brightness

[moses0101]

My screen went dim if I went to some black colored website or whatever something that I open shows up in black , And also became more bright than usual when I'm on some almost white colored website or whatever thing that is white..

Not sure what problem is this..

Will it be an Issue caused by me ? I mean physical damage because I have open it up once and re-apply the thermal paste to both gpu and cpu .. it is a normal thermal paste but will it some how damage it ?

Please help............

[TimeLion724]

The problem may be a power issue, the options setting might have gotten changed with a driver update.