gtmtnbiker wrote:No, having a smaller extension cord is not the reason why your PS3 YLOD. A power supply on a modern electronic device like the PS3 is designed to handle different input AC voltages and convert it to DC. Plugging another device like the 360 will have no effect on the PS3 and your TV.
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Take into account everything pulling from one circuit breaker. Multiple outlets and lighting all pulling power, usually from more then one room. With the HDTV sucking power already, and the 360 pulling 203 watts, it just makes sense to shutdown the 360 before starting up the PS3. Your earlier mention of a warm extension cord points to a problem. Too much resistance in that cord causing spikes and surges, not good for electronics or the fan and drive motors. Even if your point has merit, no reason to guesstimate risk it, a twenty dollar heavy duty cord is a good investment.