Kb do you have air blowing out the top of the case in the back?If you do then the fan on your power supply works.If it does not have air blowing out then I would bring it to a shop and they will replace the power supply.There should be just two screws holding the left side of the case on.These screws are on the back of the case on the left side.Remove those and slide the case side to the rear of the case this should expose the inside of the computer.somewhere in the middle or more towards the top should be another fan spinning If it is not spinning turn it off and get it replaced.If it is spinning I would bring it to a shop and pay to have it diagnosed.Once you get the left side off it will be obvios what I am talking about.You cant hurt anything by removing the side of the case and looking in!