Apple's MagSafe adapter solved the number one source of catastrophic laptop damage; pets, children, and oblivious adults often tripped over the old-style power adapters and brought the entire device crashing to the floor. But the MagSafe adapter came with problems of its own. Fraying cables were a fairly common occurrence among the first-gen adapters, and the problem became widespread enough that Apple started replacing frayed MagSafe adapters free of charge in 2008.
Three years later, most of the MacBooks and MacBook Pros with those old-style adapters are now out of warranty; Apple redesigned the MagSafe connector
