Monitor or video card dying?

Hi guys. This is my first post. This has been ongoing now for about a month/month and a half. I built my new computer back in March. The video card is an Abit Radeon RX-700 Pro 256MB PCI-Ex card. The monitor is about 6 years old - an old HP Pavilion v50 that went with the old computer. I guess I am expecting the monitor to die, but not the video card being it is less than a year old. Since the issue began, the monitor display will "twitch" on the left and right sides. It is nothing drastic, just a bit annoying. One day when I went to start it up, there were white lines all over the screen. Since this happened immediately at startup, I know it is one of the two. I'm running Windows XP Pro with SP2. When I got logged on and tried to open Firefox, the computer froze. I pressed reset and the display was normal again. Despite the "twitching", everything was normal. About a week ago, the white lines returned. When I got to the logon screen, I didn't want to logon and have the computer freeze again (if it would). Instead I rebooted. The white lines became more congested. That was a surprise. So, when I got to the logon screen again, I pressed the reset button on the tower. The display went back to normal. On this old HP monitor, the manufacturer recommends no higher than 85Hz for the refresh rate at 1024x768 MAX. Safe limits are 60Hz at 1024x768. Running at 800x600 (15", 13.9" viewable) I can run 85Hz. Anyway, on October 13 I downloaded a demo of Loc-On: Modern Air Combat. I only played for about 30 minutes (too complicated ). About 25 minutes in I decided to check out the options in more detail. I think the resolution was 1024x768 (I don't remember). The refresh rate was 100Hz! Could running it that high have caused the monitor any damage? Also, about a month before that, I downloaded the Age of Empires III demo. The game runs 1024x768 default. The refresh rate was higher than the safe limits of 60Hz for this monitor. I don't recall exactly the number, but I think it was in the 70s or 80s. Could that have contributed in some way? I still hope it is the monitor (it is 6 years old after all ). If it is the video card, I may just get a new, better one rather than get this one fixed. I'm hoping the video card is ok, being that it is less than a year old. Any help is REALLY appreciated!

Regarding the white lines issue because I didn't completely read all of your post. If you see the white lines on your display then unplug the video cable from your grapics card and after a second your monitor will display "no signal found" and probably show the red, green, and blue colors. If the white lines are still there then it's your monitor. If they are not then something is causing the problem.

Thanks guys. I guess I forgot about this thread.

That sounds like a good idea, but my monitor is so old that it doesn't even display that when there is no signal. It is just a blank screen and the little power light turns to amber.

The monitor is still acting funny, but it is now doing some other weird things. I am thinking it is the monitor. On a couple occasions now, the monitor display started to blank out. There was a bright flash down the center of the screen - like a thin "slice." The screen started going in towards that slice while darkening somewhat. The monitor also made a clicking sound as one does, say when it turns on or off. The display then returns to normal.

1.5" every year? Wow.