Steve,

Denny had some good ideas on how to get your radio fixed by local hams
etc. A radio that is completely dead is easy to troubleshoot -
intermittents are much trickier.

Have you checked the power cable to the radio? Unplug it from the rig
and use the meter and lightbulb to verify that all is OK on the
connecter end that plugs in to the radio. There should be fuses in the
positive and negative leads of the cable. You need to test them with a
meter. Often they look OK to the eye but they are blown. If you don't
have a meter try replacements of the correct amperage rating.

If you decide to take the covers off here are a few tips. Disconnect
the power cable. Get a container to store the screws. They often get
lost and it is impossible to find exact replacements. Do not remove
any boards etc. - this is best left to someone with experience and
proper test equipment. Look in the vicinity of the power socket -
anything burnt or scorched traces on the boards?

I took a preliminary look at the circuit drawings for the FT-890. It
looks like there is a relay that is activated by the power switch.
When the radio was working did you hear a "click" when you turned it
on?? If this relay is blown this is not an expensive repair.

Steve - it can be discouraging when this happens but don't give up on
your radio. Local hams are often willing to help out. There are some
FT-890 owners on the Yahoo group at
http://groups.yahoo.com/group/FT-890

Good luck - Roger