Welcome to the MacNN Forums.

Big Mac · Apr 21, 2006, 05:33 AM

I am a bit concerned about something I have seen at least twice now in the last few days. About fifteen seconds after waking up my G5 I see thin red lines a few inches long shimmering on the right side of my display. It goes away after about five seconds, and then I will not see it again for the duration of my work session. It looks to me like some sort of interference, but that cannot be because it only happens after a cold wake-up. If I put it back to sleep and then leave for only a short period of time this does not occur. That to me says it's a thermal issue. I have performed no recent hardware modifications at all, and the only substantial change in recent times was the update to 10.4.6. I really hope this is a software issue, but that's not what it looks like to me. Anyone have insight?

mduell · Apr 21, 2006, 05:55 AM

I'd guess something is coming lose due to thermal stress (expansion and contraction) on your video card or in your display (which I assume is an LCD; if it's a CRT, then I'd lean toward the video card).

Big Mac · Apr 21, 2006, 05:58 AM

terrific. . . well, thank you for the input.

reader50 · Apr 21, 2006, 01:38 PM

Try unplugging the monitor data cable. Clean the pins, reconnect.

Big Mac · Apr 21, 2006, 01:56 PM

I'll give that a try, reader50. . .

Big Mac · May 1, 2006, 07:15 PM

Well, this is a really intermittent issue. I sprayed the cables and port with compressed air and reconnected everything, but while the reduced the problem it did not eliminate it completely. I then went for a number of days without seeing the lines, yet they appeared again today. I'm starting to doubt it's a thermal issue because on most days my G5 will wake up without incident after being in sleep mode for the whole night. I really hope it's the monitor and not my 9800XT. This will likely give me the excuse I have been looking for to replace this Samsung CRT with an LCD, although mduell says it's likely my graphics card because I'm on a CRT. . . reader50, would you use a Q-tip and rubbing alcohol to clean the cable's pins?

reader50 · May 1, 2006, 10:38 PM

Originally Posted by Big Mac

... reader50, would you use a Q-tip and rubbing alcohol to clean the cable's pins?

Um, no. After you take the shipping into account, especially if the monitor is permanently attached to the cable, it wouldn't be economic.

Rather than ship it to me for Q-tip & alcohol cleaning, I'd suggest getting a can of zero-residue electronics cleaner from Radio Shack. Rubbing alcohol seemed to leave a fine residue the few times I tried it on electronic contacts.

Big Mac · May 2, 2006, 02:47 AM

Originally Posted by reader50

Um, no. After you take the shipping into account, especially if the monitor is permanently attached to the cable, it wouldn't be economic.

Big Mac · May 4, 2006, 05:23 AM

Well, good news, it's my cheap-o CRT (Samsung 793mb) at fault! I just found confirmation of that fact here. I really should have googled instead of worrying needlessly.