Problem with welcome screen of Toshiba Satellite laptop: Snowy screen!

Hello all,
Last year my Toshiba Satellite C75-B7193 laptop started showing a snowy screen for approximately 30 seconds (sometimes less), but just the bottom 3/4 of it, when I flipped the screen up. It was around september. Then I left town to work and, in another city with a different weather, the screen didn't cause any issues. When I came back in January the snowy screen appeared again, same issue.

I have several theories about it:
1. A faulty ribbon (but why only when I wake the laptop up?)
2. Room temperature (that may be an issue, it's cold in the room when that happens)
3. Problems with the graphic card

Any suggestions on how to solve this issue?

Seems to be the temperature as when it warms up or on a warm place it works normal.
How cold is the room temperature?

I'm sure it isn't dust in the fan/ hard drive. Quite sure it's the temperature.

Thank you MHz. I will leave this thread open in case other people have similar issues like mine. Most appreciated.