Protecting device includes a main body and a removable cover. An embodiment of a fault analysis apparatus includes a test pattern source to provide a test pattern for an interconnection between a transmitter and a receiver, the interconnection having a transmitter end and a receiver end, the interconnection including a first wire and a second wire, the transmitter transmitting the test pattern on the first wire to the receiver. The first logic circuit is capable of obtaining first data and sending second data.