Curious display panel on 200T

[Tony Guttmann <tonyg@ms.unimelb.edu.au>]

Dear q-listers,

Usually, when I turn on the ignition, my display panel says
"O K" in nice orange characters. Recently, it has taken to
displaying 2 or 3 thin, orange horizontal lines instead - and
sometimes with a warning noise of indeterminate form.

It might do this for 2 or 3 starts, then show OK the next time,
then revert to the 2/3 line behaviour.

Perhaps the following is related: Low power steering fluid
level is not being reported on the panel. Shorting out
the switch on the reservoir doesn't report the fault either.

Any tips where to look/what's wrong?

Many thanks in advance, as usual.

Tony
'90 200T (slush).