I have just purchased a condo with an older model electric cooktop. I don't have an instruction manual and I don't know the model number. The electronic touch controls have just started blinking on at the same time. There is a 'beep' and then they all continue to blink until I turn them off. Then within 10 -20 minutes they turn on again. Can you please tell me why is this happening and how do I stop it? Also, where can I locate the Model number so that I can get a manual?