Strange screen artefacts

[danIrl]

I am using composite out to my CRT TV. Picture quality is acceptable, but every now and again, usually after prolonged viewing, a strange interference pattern is sort of overlayed over the TV screen. It is like a honeycomb pattern, in a grid that moves hoizontally across the screen.

SWitching between AV and back again on the TV makes no difference. Stop/starting a reconding on the PVR makes no difference either. The only way I have found to fix it is to restart the machine. Logging into the machine using VNC, the picture appears normal.

I am using VMR9 mode. I presume it is related to my video card... but then why it only occurs intermittently is strange.

Anyone come across this before?

[Koenie]

Yes, I see the same. I have tested several video cards and it seems to be realted. My suns ATI 9600 PRO seems the worst, an Nvidia 6200 or my ATI 7500 AIW are similar but better than the 9600 PRO.

I tried with other cables, different cable routing, other connector to the TV, s-video out with an s-video to composite converter or straight composite from the card. This all seems to have no influence. I would like to test a really good quality cable but do not have one.

From the mediaMVP there is no interference at all (also uses composite though trough a scart cable).

[stefan]

Could it be a heat issue?

[chud]

i assume you guys are running the latest video drivers from the respective manufacturers...

[danIrl]

I do not believe it is heat. I have a fairly large case, with low temperatures last time I checked. I replaced the original fan on the video card with a Zalman. Also if I reboot the machine, it is fine and will play fine for another hour or so.

Pretty recent video drivers are loaded... which havent changed much for the old GeForce4 MX ;-)