Ok, a friend of mine has some problems with his PS3. The thing is, each problem is different on every other game he has. He can go online just fine and use any system menus without trouble, it's when he's actually playing the game that the errors pop up. For example, on Guitar Hero, the graphics won't display properly and a giant block/line/thing appears over everything (like one big giant censor box) and on the create a character screen in Oblivion the faces for the characters will be lowered and physically pass through the chest and leave the eyes just floating where the forehead is.
Anyone have any general advice or what to do aside from buying a new one? He's willing to crack it open, so would it be a good idea to dust off the system from the inside, particularly the disc reader?