Only way stereo comes out as mono is if there is a short circuit between the two channels. Suggest carefully check the cabling from cartridge to mc stage. Include the wiring within the arm. This is easy with a meter. If ok try bypassing phono stage...volume will be very low but may reveal whether short is in the phono stage.
Take it other sources play stereo normally?
You correctly chose alternate line inputs as otherwise there would be 2 riaa equalisations in series.
Good luck. Let us know how you solved the problem.
Take it other sources play stereo normally?
You correctly chose alternate line inputs as otherwise there would be 2 riaa equalisations in series.
Good luck. Let us know how you solved the problem.