Broken laptop screen while external works without a problem

[JKKdev]

I've got a HP ProBook 4520s which started acting up in the last month or so. The image on the laptop screen started tearing while the image on the external screen was completely fine (http/imgur.com/erZjXA4). What's more this problem doesn't occure all the time. I have never seen it tear in bios/windows start up screen. The first time you can spot the problem is when you get to the account selection screen where the blue background of Windows 7 takes on a slightly yellow hue in some parts of the screen.

Do you think this is caused by the graphics chip or is there another possible reason for this kind of an issue?

Thank you for your suggestions
Regards, JKKDev.

PS: The problems started when (or shortly after) I started using the external monitor.

EDIT 1: I should probably also state that the first couple of times this happened the simple act of changing the focused window from full-screen to "windowed" solved the problem completely just to reappear as soon as the focused window was full-screen again. Just today the problem was getting a bit obnoxious as the laptop just wouldn't start without the problem appearing as soon as the login screen was shown. The only way I was able to "solve" it was to switch into duplicate mode in which the screen resolution was changed from native to a 4:3 resolution however this time the yellow hue persisted even tho the tearing was gone.

 

[penguintech]

Usually, when there is a problem with the GPU, the issue is mirrored on the external monitor as well. If your picture is clean on the external and you are only have issues on the laptop screen itself, then it sounds more like there is an issue with your laptop LCD screen or the Video cable connection from the LCD screen to the motherboard.

 

[scout_03]

does it made it if you use only the laptop screen as main and remove the external from laptop dont forget to set gpu to a single screen .

 

[JKKdev]

does it made it if you use only the laptop screen as main and remove the external from laptop dont forget to set gpu to a single screen .

Please read the edit tag in the original post. No matter which mode I put the gpu in the problem persists except if I change the resolution of the screen.

 

[scout_03]

so if you put the laptop secreen resolution to default it work as it should so when you ajust to the eternal it could be overscanning the main one ,so use the laptop default one and check in the gpu control panel if you dont have something similar to adapt panel to screen size and scale by gpu .

 

[JKKdev]

so if you put the laptop secreen resolution to default it work as it should so when you ajust to the eternal it could be overscanning the main one ,so use the laptop default one and check in the gpu control panel if you dont have something similar to adapt panel to screen size and scale by gpu .

The resolution at which the tearing stops is not native (default) and the yellow hue still persists so this is not a solution to the problem it is just a temporary fix to be able to even work inside windows (currently however the problem isn't present and the laptop works just fine but it won't for long, I'm sure of that).

 

[scout_03]

try this on sensor page to see if it could read your temp http/www.hwinfo.com/download.php when was the last time ou dust the fan off your gpu could be overhathing .