Cheryl, you probably have a case of CPU asphyxiation (Dust preventing proper cooling). That is usually the 15 minute collapse symptom. Pull the plug, remove the cover, carefully remove what dust is piled inside the box (that is not the 15 minute problem). The CPU is a chip on the big board with an assembly over it and usually a fan built in. The fan is probably unable to move due to dust and the assembly has fins that are probably full of dust. That is the likely problem. If it looks very dusty, go to Radio Shack or Good Guys and pick up a can of spray duster. It is compressed gas (non-flammable) in an aerosol can with a 5″ plastic tube taped to the side. Wear a dust mask like you would for SARS (or a bandanna) and a pair of glasses to protect your eyes. Carefully blow the dust away from the fan and the fins around the CPU (the fan blades break easily but the duster gas won’t damage them). Make every puff count – there is not a lot of gas in the can. Get help if possible. Once the fan and fins seem clear you are probably OK. There is a closed metal box that is the power supply and it has a fan that is supposed to turn and cool it. At least be sure that the fan is free to turn. Get some dust out of the power supply if necessary – don’t break anything. Put the cover back and re-attach the power. If there was not a lot of dust around the CPU fins, the fan motor may have worn out and need to be replaced but do the cleaning first and get help if you need to replace anything.
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