Wondering if anyone has experienced this before...I have not been working with my Mac for very long so just checking on this.

When I first boot up my Mac everything goes fine and then after about 10-15 seconds of just sitting there, the display flashes off and then on again.
My buddy who knows more about Mac then me said that something is not right. I downloaded the newest upgrade of Tiger and it still does it. Just wondering if anyone else with a PowerMac G5 with FCP 5.0 has seen the same thing happen.

I've seen that too Jay, but I'm running a CRT about as old as I am :) so I just figured it was the display...

I also saw this on my old CRT monitor (which finally died about a week ago). You've neglected to tell us the most important thing however. What kind of display is it? LCD? CRT? Size? Brand? Age? Etc...

Sorry for not totally explaining everything...I just wanted to see if someone else has seen this happen before. My situation is...I just purchased 6 weeks ago a PowerMac G5 Dual 2.5 Ghz with a 23" Apple Cinema Display. Not knowing much about Mac, I had the company I purchased FCP from (apple reseller) install everything for me and set everything up.

Do you think this may be a display problem?

Thanks for your help.

Still not clear on exactly what you're describing. Does the display just flash like this once when you boot? Or does it happen regularly? When you first login your preferences are loaded, and depending on the monitor settings this may be different from the default that's displayed at system startup. It's common for the display to flash then. Also during the boot process you may see some brief flashes.

But if it's flashing periodically as you work something's wrong. Also your energy saver settings will affect whether the display goes out after a period of inactivity, but I assume that's not what you're describing.

Do you have another screen you can plug into the computer for a test (you should have gotten a VGA adaptor with the computer, or at least they used to include one). That might help isolate whether it's the graphics card or monitor itself. You could also try hooking up the 23" LCD to another computer, anything with DVI should work.

After it fully boots up and is sitting at the desktop for about 10-15 seconds, then it flashes off then comes back (it actually flashes to a blue screen then back to the desktop).

Thanks...I will try to figure this out with some of the advice you gave me.
I appreciate it!