Bizarre screen incident on my iMac G5

[reykjavik]

So after 3 hours my monitor turns off and turns back on if I move the mouse. Tonight I came back to my comp and turned it back on and a quarter of an inch of the lcd screen right above the dock kind of scrambled a bit, as if it were snow on a TV. This occurred while the screen was "warming up" and getting brighter and then it stopped. It only happened once (that I know of) and it only lasted about 1-2 seconds.

What does this mean? Anyone have a similar instance?

 

[EricNau]

Hasn't happened to me. I wouldn't worry about it if it doesn't happen again.

 

[Crackamac]

there might be a prob

I have a rev A imac g5 20" at work ( I ordered it right after they were announced) and sometime last year, it developed wierd probs, the first symptom was a garbled screen. I would turn it on and the grey apple logo would loose it's definition and then I get to the login screen, it would look like every other line would shift 1 or 2 pixels to the right. when I would get into the system, some of my windows would corrupt. this only happened twice and I dismissed it, a reboot would fix it. finally 1 day, about 2 weeks later I would get kernal panics and the line shifting would happen constantly with no reboots fixing it. I called applecare and they told me that there was a prob with their capaciators popping and they would send a tech to switch out the mainboard. So, being a courious guy, I popped off the back cover to look and sure enough , a number of capaciators were bulging. so if I were you, I would make a backup of the data and call applecare, esp if it's a rev A imacg5.
on a side note, once the board was replaced, it's been steady ever since, no more probs

 

[reykjavik]

I have a rev A imac g5 20" at work ( I ordered it right after they were announced) and sometime last year, it developed wierd probs, the first symptom was a garbled screen. I would turn it on and the grey apple logo would loose it's definition and then I get to the login screen, it would look like every other line would shift 1 or 2 pixels to the right. when I would get into the system, some of my windows would corrupt. this only happened twice and I dismissed it, a reboot would fix it. finally 1 day, about 2 weeks later I would get kernal panics and the line shifting would happen constantly with no reboots fixing it. I called applecare and they told me that there was a prob with their capaciators popping and they would send a tech to switch out the mainboard. So, being a courious guy, I popped off the back cover to look and sure enough , a number of capaciators were bulging. so if I were you, I would make a backup of the data and call applecare, esp if it's a rev A imacg5.
on a side note, once the board was replaced, it's been steady ever since, no more probs

I'm nto entirely sure by what you mean as rev A but I too had the original first release of the 17 inch iMac and I too had to have the logic board replaced (twice). But then I gave that one (which after the repacements worked fine) to my dad and got myself a newer 17 inch with the isight and crisper display (and no blarring fans). I had the exact same experience as you as far as symptoms go but this isn't really that, its a little different. I've tried putting my monitor to sleep and waking it again a couple of time and haven't seen it since, so maybe it was just a fluke thing. I definitely will work on backing up my stuff though.