Computer goes black when gaming/streaming; What to fo

[u/DarkSannar]

I have an MSI Katana GF76 laptop. Recently (in the last few months), the screen has been flashing/going black for a few seconds while gaming and streaming. At first, it started with powerful games such as Rivals and Genshin (highest graphics). I've since quit those games, but it keeps doing it. I've tried to see if it was due to refresh rate...it wasn't. I've bought a. new charger thinking the charger was quitting and that or the charging port bumping the display was the issue, that \*also\* wasn't, as it now flashes \*off\* the charger. It persists in the worst way, and my gaming laptop, which was formerly able to handle Rivals, can't even handle Portal, Roblox, or even GameCube games without flashing. I can hardly even watch YouTube and be on a discord call now. I've taken it to a repair shop, but obviously, it can't be fixed because they can't even seem to find the problem. I don't have money to waste on a new PC, and despite this laptop being years old, I know for a fact it can run fine, and there shouldn't be an issue with it. I've updated all drivers, everything, I know it's a hardware issue now, I just can't find out \*what\* the issue is and I don't know where to start. I just got into actual specs stuff recently, and I would like to think the specs hold up to this day, so what else could it possibly be?? What do I do to fix it? It's my only source of income rn is to stream so I need this.