[Kenwood] TS850-SAT ATU squealing

[Brian Jones]

My TS-850SAT sat in storage for a couple of years (while I was exploring an
Elecraft K2). When I used it for the first time out of storage the ATU
squealed badly when auto-tuning band changes. After a couple of hours this
went away so I assumed it was condensation or temperature induced. However a
few months later it has come back, and this time the rig has been in a warm
shack and was used only a couple of days ago.

It with the lid off it sounds like it is coming from the rear of the ATU
unit. It looks fairly easy to remove the ATU (apart from those white
connectors with multicolour wires to both the filter unit and front board
look as if there is a 'knack' to removing them). Once out I assume the ATU
itself is easy to disassemble.

Any idea what is likely to be the cause and whether removing the ATU and
lubricating some mechanical part is needed or is it likely to be part
replacement?

Thanks

Brian G0UKB