Very Low Sound From Lines.

Hello all.

I have a Pioneer DJM250MK2 and have 2 Technics 1210 Mk2s connected. I have had them connected through "Line" for about a year now. Last week all was well but this week when I switched them on, the sound was barely audible from either Turntable. Switching the Amp and mixer to full volume I can hear sound but its very low. If I connect through "Phono" all is fine. I live in Mansfield Notts, Does anyone know where I can take it to be fixed please.