Smeg A2 double oven ?

Have replaced main oven selector switch as would only let me select one option. Now all choices available. Thermostat also seems to have failed so have replaced but whilst sure thermostat is working as clicks in right places as oven heats it is not controlling oven which just carries on getting hotter and hotter. Had already replaced main oven element few weeks back. Worried when lifting cooker top that some connections might have come off selector switch or thermostat and two are not communicating Does any of this make sense and any help appreciated. The little red light on cooker front panel is not illuminating