KR 6400 Balance issue

Hi guys-

I have a Kenwood KR6400 that has been thoroughly cleaned and lubed with deoxit. After cleaning (twice) I still have a balance issue. When I move the balance dial to the left channel, I hear slightly weak sound from the left and very faint sound still coming from the right. With the balance dial set to the right channel, I hear nothing from the left and good sound from the right as expected.

Where do I begin to look? This happens across all sources, and I did clean the "Normal/Seperate" switch on the rear of the unit along with everything else.

what happens when centred on the balance ?
what happens in the different modes ?

Centered balance leaves the right channel stronger than the left. It can be made roughly equally by skewing the balance a little to the left.

I'll have to play more with the modes to see what happens.

The weak side stays with the speaker no matter what mode I select, and is also the same through headphones. To address the obvious, yes I have tried swapping the speakers and have tried the other speaker inputs