Wurlitzer speaker problem

I have a Wurlitzer 3500 and it sounds great. The problem is it only sounds great through the two speakers on the left, bottom and top. Also have a receiver plugged into the phono jacks and only get sound from the left also. I've checked the wiring and everything looks right. A channel has both black wires on the G screw, Red's on B screw and the white wires are on A screw on the B channel. I have a manual but am not quite understanding where this is wrong. Could this be a amp problem? Any help would be appreciated.

Murry,
Swap the red-white wires ( attach them to the "A" screws", if no other speakers are in use) and see if the loss of sound changes sides--if so, it is an amp problem--if not, it's a wiring, or speaker problem--Ron Rich