[Kenwood] TS-830S RF Attenuator Question

[w0ng at comcast.net]

Hello All - 



I recently acquired a 7 million serial number TS-830S to repair, restore and keep in the shack. 



I have no history about previous owner's issues with this rig. 



The RF ATT button when pushed in cuts the volume of the normally loud received signal to almost zero. 



Other 830S's I've owned only cut the volume about in half with still very good audio and completely intelligible but no overload. 



Any ideas why this particular rig's RF ATTENUATOR cuts the volume to almost zero and how to remedy it? 



I studied the schematic but nothing jumps out at me so far. 



Upon inspection, all the wiring & the switch pc board are unmolested. 



Tnx, Bill, w0ng