I have a problem with games. Whenever I run a game, black screen shows up, my computer freezes and I can do nothing, can't even shut down the PC so I must restart it. The web games work normally and I can surf and do stuff on PC with no problems but I just can't play games.
So someone gives you advice about replacing your no name PSU which probably supplies no where near the 400w it states it has, and you dismiss it. Id say exactly the same thing, its more than likely your PSU.