to be faulty i think depend your luck also, for normal used what i saw is around 2 years or more, filter capacitors ( power supply board) become bulged and leaked on top.Capacitors breakdown was very common in the LCD Monitor because of it compact design where the heat have difficulty to transfer out due to the power supply board was covered by an aluminum shielding. give u the model what i already facing
Benq - 17" FP71G----inverter problem
Packacd Bell 15"--forgot model
HP 17" hp 1702---capacitor problem
Acer AL1717----capacitor problem
benq 17" T705....inverter problem

Also depend how many hours/day you use it...better switch off when u leave it.