Mymonitor is black and the on button from the monitor is green and is flashing

I havent seen this question asked, and believe me i have searched. i have compaq presario, windows xp media edition 2005, 64 amd processor, model # SR2017CL, with HP 1703 17" monitor. Prob-put computer in hibernate mode other evening, without turning it off. when i woke up, screen had diagonal lines going across it. i rebooted, well manually restarted, since comp would not respond.
Message comes up white with black writing, essentially, prob with active desktop, restore or turn off. i tried to turn off and screen went back to diag. lines. looks like the horizontal hold of a tv screen is asque. tried adjusting monitor to no avail.
tried a few more times, was fine for a few mins then went to same thing. now when i turn monitor on it blinks red, blue, and so on.
just whole screen that color. so i am at the point where i dont
know if its the comp or the monitor. (i am quite a newby)
ty for any help you can give
ellie