The turntable input is silent, weak, noisy, or distorted.
Safe first checks
Confirm the turntable is connected to PHONO, not an auxiliary input.
Verify that the turntable ground wire is connected to the ground terminal.
Test another source on AUX to confirm the amplifier section works.
Check that the cartridge leads are secure and the stylus is not damaged.
Next step
Record the cartridge type and whether the problem is one channel or both.
Bench Technician Steps
This is the model of work a qualified electronics technician follows using the exact service manual and suitable test equipment. It is not a do-it-yourself instruction to work on energized equipment.
Confirm the cartridge type and expected signal level before evaluating the phono stage.
Trace the phono input, grounding, selector, and preamplifier path with the service manual; compare channels where applicable.
Avoid substituting a generic cartridge or stylus as a diagnosis without confirming electrical and mechanical compatibility.