Computer monitor driving me crazy. Can you help?

It is taking me ages to get my monitor to work normally. This has been going of for a week. Most time the screen is just coming up white with sometimes a very faint wording eg Windows in the background. I have checked all cables, plugs etc. Pretty sure it is not the on/off power button as this happens even if I have left the monitor absolutely normal and not turned the power button off. I can press and press the power button, reboot the computer etc. and suddenly give a press and monitor works perfectly. Once working no problem whatsoever but next time I return it's the samer carry on. I would very thankful if anyone could help me and please bear in mind I am not technical in any way so you would have to speak to me in basic language. Thanks!