I have a Slim PS2 model SCPH-77001 and a green dot matrix infinity modchip. I tried opening the PS2 and successfully got to the point where there are only metal plates protecting the motherboard, but there are four screws that are impossible to get out. I asked my friend who has a degree in electrical engineering and he said that they look like they were welded on. I have searched to find a solution but had no luck. Did anybody successfully got to the motherboard of a SCPH-77001? If its not just a matter of unscrewing then what other tools do I need to use? Here are the four screws I am talking about. This is how it looks on the other side.