Try swaping the phono input into the amplifier to see if the sound still remains through the working channel. If it does this would indicate that the cartridge and cables to the amplifier art ok. If the sound swaps chanels this indicates that the cartridge or cables are at fault.
The speakers are so close to each other it is hard to hear stereo, try disconnecting lt and rt side speakers one at a time see if you have output from each side of the amp.
left chanel works but not the right chanel---thanks for suggestions--both speakers are good because I swapped wires from one speaker to the other to test