Hi, we have a September 2010 2.8 Mac Pro desktop running into a Formac monitor. Generally been running well for the last six years. Today though the monitor would come on when I pressed the on button then last for a short while and switch off I then press the on button again and same thing happens. Is this a problem with the monitor or the Mac? If it is a problem with the monitor can I purchase and use a normal one or do I have to buy another with a DVI plug? Would really appreciate your assistance!