G5 Weird Digital Grid Pattern around Icons

Hello. I have a 5 year old PowerPC G5 running Mac OS X version 10.4.11. It's just developed this weird glitch. The desktop icons, menu bar and cursor are surrounded by squares of dots in a grid pattern. I've uploaded a snapshot of it. Neither restarting, nor shutting down and restarting have had any effect. Has anyone else had this problem? If so, is there something I can do to fix it?

Yes! My old G5 developed the identical symptoms! It was particularly obvious with graphics.

I put up with it for some considerable time until I eventually took it into my local Apple Service Centre and they diagnosed that the problem was unfortunately with the logic board. I had the board replaced and that solved the problem.

In addition to my last post, here's a screen shot I took of my G5 screen!

Good to know! Thanks so much John.

For starters go into System preferences > Universal Access and turn off Voice Over and Zoom if they are on, as these can accidentally be activated by using Keyboard Shortcuts.

If all is okay there, check the fan unit, where fitted, on your graphics card is actually running as they do become clogged with dust, and maybe even die.