At the beginning of the year my power supply died and Apple changed both of them. 4 months later, happened again. Now, 4 months later, it is happening again! The power supply is plugged into a power strip with other electronics as well. The power supply keeps the laptop alive but won't charge it. If you unplug it the battery drains like normal. No light on charger, other chargers charge the laptop. Do I have dirty power at my house that keeps blowing it? Nothing else has been effected. Can a computer effect the charger? Please help! Still have 6 mos of applecare, but am tired of this. Would like to find solution.