Steve,

I searched through the Yahoo Group - Amateur Repairs for similar "dead"
FT-890 problems. I found one which may be of interest.

As the unit ages oxide builds up on the connector mating surfaces and
sometimes leads to erratic operation. In one case, an FT-890 had
exactly your symptons - dead and the front panel power switch did
nothing. The solution was to disconnect all power and external
connections and remove the covers (saving the screws). Then carefully
disconnect and reconnect, one by one, all the connectors on the
various boards. The disconnect/reconnect scrapes away some of the
oxide on the connectors and restores a low resistance connection. Then
reassemble the unit and try powering up again. Make sure you have
discharged yourself for static (wear cotton clothes and no nylon
carpet!!) prior to starting the job.

If this solves your problem you may be OK for a while. In a few months
it may come back. In that case you should buy some deoxidant from a
radio repair outlet and use it on the contacts for a longer term
solution.

Hope one of these ideas works and it is not a component failure.

Regards - Roger