[Kenwood] TS-830S problem

[EOLEEJR at aol.com]

My TS-830S has an annoying background static popping noise. It is not  real 
loud and sounds similar to a volume control that needs cleaned. I have used  
de-oxit on all controls, tightened all screws on circuit boards, checked all  
connections. Non of the controls or switches have any effect on the noise and  
even when you transmit the noise can be heard from the speaker. Has anyone had  
this problem or any suggestions what to check? Also, can the tension on the 
VFO  knob be tightened? I have checked the service manual and cannot find any  
information about this. Any help would be appreciated.
 
Thanks,
Gene
WB4NUM