Problem solved. Re-seated all the connectors on the main board and the
tuner is now working.

73, Bernie

wrote:
My ICOM AT500 has a fault where the auto tuner portion works properly
on transmit but on receive, the tuner retunes to a non matched setting.


The presets work and I can manualy tune the tuner via the presets (but
that defeats the point of having an auto tuner)

Problems began when the shaft on one of the motors come loose. I
believe I have everything mechanically back together correctly as there
seems no way that the auto tuner portion should work on transmit and
then de-tune on receive.

This unit is full of analog circuits and I have no clue where to start.

Any help or suggestions would be appreciated.

73, Bernie, VE3FWF