2000xl sampling problem

Hi everyone!

I've recently bought 2000xl and I'm totally new in this area. Up to now, MP seemed to be fine, but when I finally got rest of the stuff essential for sampling, I found out that unfortunately there might be a fault Basically, I'm tryin' to sample some first sounds from a turntable, of course through a DJ mixer (Vestax), following each step mentioned in tutorial... but the coming signal seems to be too weak - I have to turn 'record gain' knob up to maximum to get to level meter (treshold: -20). Even if it gets to level meter, there is no sound when I play, just some strange distorted s**t. I don't know if it's technical fault of MPC or maybe mixer?? RCA cables are good, I'm sure about that. Even if I'm changing monitor from L/R to 8 outs it doesn't receive a sample as it is supposed to do... I would really appreciate any ideas, suggestions or advices before I decide to send it for service....

Yeah, it's connected this way, and all mixer knobs are set in the middle positioning, so it shouldn't cut the volume. I'm worried that it might be some input problem, cause when I slightly press RCA toward the MP, the signal seems to be stronger, but still not strong enough.

Thanks for the hint, man I will ask someone skilled for soldering then.