It could be a lot of things. Fortunately, many of the things that it could
be are merely mechanical issues with connectors or IC sockets. Even if you
have absolutely no electronic tools, try reseating all the connectors (but
don't touch the membrane switch tails). If still no joy, then try prying the
memory chips up slightly and pushing them back down. (Do these things with
the power off, obviously.) If you have a voltmeter, you can check the
various supply voltages, and also make sure the DC OK and AC OK signals from
the power supply are high.
--
Ciao, Paul D. DeRocco
Paul mailto:
pderocco@...