djm 450

disappointment from djm 450 i own it 2 and a half years light use as a backup mixer and the two chanel faders give up...i need to change booth.i own the djm 800  two djm 900 and one djm 850 .i need to change only one chanel fader on 800 after heavy use and some tact swich on the others..i use all professional for more than ten years.every day...this djm 450 is crap..the effects is useless and the aux cd in have no cue prelisten option..no balance pot and the set curve for all faders is useless..the worst djm ever with high price.