Flickering screen (black flash)

[heinkel_111]

I have a nvidia 8600 GT graphics card, with 2 SAmsung 204B LCD displays.
Until now it has been working fine, but as I write this, the left screen is flickering. Several times a minute it turns all black and then goes back to ordinary display. I don't know, but I suspect this is hardware related, it could be the screen OR the graphics card.


How do I sort out what the problem really is? Anybody familiar with these symptoms?

I run Kubuntu 7.10 64 bit version. I use Kwin. The problem is also there, but less, when running windows.....

Any help appreciated.

[integr8e]

Re: Flickering screen (black flash)

After some googling, I found this thread describing a similar problem to yours. I hope it helps

[Snowhog]

Re: Flickering screen (black flash)

You might also benefit from reviewing dibl's Nvidia 8800GTS -- Card and Driver Tips post.

[heinkel_111]

Re: Flickering screen (black flash)

I apologize for late reply, but something came up and I haven't had the time for hacking in the last week. However, that seemed to solve the problem it is no longer a big issue.

I suspect that it is hardware and not driver-related. The drivers have been working well before. The day that this problem drove me crazy, it happened almost exclusively on Linux and not on windows (I have a dual boot setup) for which reasons driver problems might have been expected, as the drivers are generally better on WinXP. However I have later noticed that it happens sometimes on my WinXP setup as well (although more rare.)

Anyway, now it doesn't happen all that often on Linux either, so I guess I'll just leave it be for now. I still don't know what the cause is, and the problem is likely still there, really. It is just that when something does not appear to be broken, it might be a waste of time trying to fix it. I'll stand by that until the next time the screen start flickering black. According to Murphy's law that is likley to happen just after I have posted this... :P

[Snowhog]

Re: Flickering screen (black flash)

These are 'external' LCD displays? How old are they? Have you ruled out that it may be the display itself?

[heinkel_111]

Re: Flickering screen (black flash)

They are external (2 x Samsung Syncmaster 204B) , in the sense that this is not a laptop system. It could be the display itself yet it was odd, that the day when I posted the original post in this thread the problems were really bad on linux and definetly less so on winxp. It is only one of the screens that get the flicker problem.

[integr8e]

Re: Flickering screen (black flash)

Try swapping monitors and see if the same one acts up on you.

[heinkel_111]

Re: Flickering screen (black flash)

Hi. I realize I posted the top post to the wrong forum, I forgot I had upgraded to Gutsy (I remember the version numbers, cause that is whn I install things. The names I don't care).

I tried to install new drivers, following dibl's instructions, but I ended up with a major disaster, at least temporary....read more here:
my compaints in dibls how to... thread

Moderator, please move thread to correct forum?

[heinkel_111]

Re: Flickering screen (black flash)

*BUMP*
Sorry for interrupting the peace and quiet on this thread but even after installing custom nvidia drivers AND swapping the monitors over, these problems persist. Whichever monitor I place to the left, I always get the flicker on the left monitor and yes I did swap the cables not just the location of the monitor but I did not swap the cables where they are plugged into the graphics card.

I am currently having problem to get my desktop to run in a sensible way at all (read my thread System freeze....need help with diagnostics for more information). I am speculating that these problems may be related somehow, maybe my graphics card (hardware) is to blame for all these problems?

Since I unpacked the card I always thought that it had a fairly skimpy power supply for a card at that level (8600 GT getting power from motherboard only, no plug for extra supply to the graphics card, which my older cards all had.

Ideas on how to proceed checking out graphics card?

[dibl]

Re: Flickering screen (black flash)

If I'm understanding that the left monitor flickers, even if you swap monitors, then the source of the flicker is clearly the graphics card, not the monitor.

It may be that there's a design issue with your card. I'm not experienced using dual monitors, so I dunno what all goes on with that setup. But it doesn't sound like something that would be related to the user-configurable software items. :P


Also, note that motors, transformers, AC power lines, and the like can induce flicker in monitors.

[heinkel_111]

Re: Flickering screen (black flash)

For completeness: I also recently changed PSU. It appears to have no effect on this problem.