My moniter keep shutting the screen off, the power light is still on, but the screen goes dark.?

its a gateway flatscreen moniter fpd1730, it's about 7 years old and all the connections are tight. It turns itself off every few seconds, to turn it back on i press the power on then turn it back on , it only stays on for a few seconds and then it shuts iutself off agin,(please excuse spelling screen is off while i type)