Display acting funny, troubleshooting help

[GagHalfrunt]

Noticed a new problem today. My display is starting to get a little funky in the extreme corners of the screen. Not flickering, but straight lines are clearly vibrating and wavering a little bit. It's only in the corners and outer edges, middle of the screen is fine. I'm guessing that it's only a matter of time until it spreads through.

Currently both my monitor and video card are fairly old, so I'm not sure which is to blame and I don't have spares to test. Monitor is a 19" CRT that's behaved perfectly for years of heavy use. Video card is an old Geforce 6600 AGP, again, heavy use for many years.

I've tried the following:

degaussing - didn't help
change refresh rate - didn't help
change resolution - didn't help
change color depth - didn't help

It doesn't seem to be heat related as it appears immediately on a cold boot and doesn't get worse as the vid card and monitor are on for a while and get warmer.

Any ideas on whether it's the monitor that's dying or if the card is the culprit?

Yes, I know I should upgrade to a newer machine and an LCD monitor, but if I can push that back until the fall it would be nice.

 

[cprince]

It's hard to say for sure whether the problem is with the monitor or the graphic card. However, I think that the problem is with the monitor. There could also be interference signals for near by devices.