External monitor issues.

[Oceanite]

Hello, I am in the process of upgrading my daily driver laptop and wanted to ask about what to do with my older unit. I have a MSI GS60 2PC. The specs are 16 gigs of ram, a 128 gig ssd, a 1 tb hdd, and it has the 860m gpu. I would like to hold on to is as it is functional for the most part, it just no longer has the power to meet my work demands. The one issue it has developed is that whenever it is plugged in via either hdmi or displayport and the graphics card turns on, the screen has a lot of tearing/ flickering. I have made sure the issue only happens when the graphics card is on and a external display is connected. I have tried multiple cables and monitors. When the graphics card is not active, it works just fine. I wanted to ask and see if anyone has had this issue and knows of a fix. I do plan to take the laptop apart and replace the thermal paste, so if there is anything I can do while I have it apart, I would like to try as well. Thank you for any input.