My monitor has started showing a small flicker after start up that lasts for about a half hour then goes away. I am taking this as a warning for impending doom. Is this a symptom of a failing monitor or video card? I hope you say monitor because Best Buy has a great deal on one I like right now.

Since it goes away after half an hour, I'd guess monitor. Have you checked all your cables and ports to be sure they are good?

These are all possibilities too... Can't remember what OS you're runnning.

https://support.microsoft.com/en-us/help/12374/windows-10-troubleshoot-screen-flickering

Running win-7 on an older computer. Never had this problem before on this computer. Seems to be something new that is developing. I checked refresh rate and that is ok. Flicker is subtle and not dramatic like a flashing. Cables have not moved or changed in years.

Just go for the new monitor Geo. You know you want to.

The 3 suggestions in that link I gave you are still good ones even for Windoww 7. But I'm kinda with oldbroad! I always keep on old 17" monitor around for when I'm working on other computers. So, you can keep this one as a backup!

If it's an LCD monitor, it's probably the backlight starting to fail.
That type of flicker is not related to the "refresh rate" in Display Settings.