Sony CPD G410R No Display

Today my monitor just quit on me for no reason. The power light flashes from green to yellow and it makes a squeaking noise. Nothing is displayed on the screen. I tried it on various computers and the same thing occurs, it also does it when it power on but not plugged into a computer. Does any one know how to fix this or should a just get a new one. Thanks for your input. Monitor is a Sony CPD G410R. 19 inch CRT