Per-Olof Litby wrote:"...won't start. Absolutely nothing happens when I turn
the
ignition key - no click from the solenoid, and obviously the starter doesn't
crank. The battery is OK. Does this indicate that the solenoid is shot?
I guess it theoretically could be the ignition switch but the instruments come
to life ...."

Check the battery connections (as in remove and clean and reinstall with
corrosion inhibitor) at the battery and at the starter and engine block ground.
It's common with a bad (loose,corroded,etc) battery connection for the
instruments etc to work (very low amp. draw) but the engine won't even try to
start (very high amp draw). With the lights or whatever on, do they do dim/go
out when you turn the key to start? Could be a bad cell in the battery also.
Get a volt/ohm meter and do some basic checks before you start throwing money
at it!
Best of luck
Mike