Hey guys so i changed mixers, i had an old ass stanton sk2, and went to the stanton rm3s, i like this mixer while i was using it at a friends, and plus it something i can afford

anywho... i'm having problems with the phono 1 input, i plug in my tt, white goes with white, red goes with red, grounder. so i turn it on and i can't hear shit in my left speaker while using phono 1, right speaker is fine.

So i checked my cartridges, double checked to make sure it was connected properly, and to no avail... same thing. my phono 3 is working perfectly also. so i take the lines out of phono 1 and plug it into phono 2, left and right speakers work just dandy!! wtf?!

any ideas?
thanks

ps. i also tried switchin the tables around and its deffo not the tables.