DJM-T1 Problem

So i have had this mixer for nearly 6 months now and all was working ok enough for me to bare since i don't take my mixer anywhere, but after a while i noticed the sound quality coming out from my monitors sounded very different to what was coming out through the head phones. I decided to use internal mode instead of external on traktor and it sounded considerably better. But now i'm faced with the problem of the cue button not working on the 2nd channel. i've spent nearly a week trying to figure whats going on. I use both CDJ's and Technics with timecode and have the latest drivers,softwares and firmwares.