[General Battuta]

At random intervals anywhere from zero seconds to several hours after startup, my screen goes black and white and remains that way. It renders properly except that all color has been replaced with greyscale.

Flickers of color can sometimes be seen where colored elements should be rendered. When shutting down, the Vista shutdown screen often displays color.

In-game in programs such as Team Fortress 2, visible texture corruption and model...stretching is visible.

Running in safe mode or uninstalling the GPU drivers fixes this problem, suggesting that the problem is with the GPU (a Radeon HD 4870.)

CPU temperature is around 25-35 C and GPU temperature is around 65 C. I am not totally inclined to think this is an overheating issue; however, leaving the computer powered off for a long time seems to extend the period before the black-and-white problem kicks in.

Thoughts and suggestions?

[Klaustrophobia]

is your card still under warranty?  i very highly doubt overheating, the 4k line can easily withstand temps of 80c.  mine (first block reference design 4850) runs at nearly constant 82c even at idle.

[headdie]

when did it start?

could it be corrupt drivers???? probably to simple.  are you using a downloaded install or as supplied with your card?

[General Battuta]

Started a few days ago after moving the computer and reseating the heatsink. It's possible the card was somehow damaged while the case was open.

Seems to have a lifetime warranty.

I am using the latest downloaded drivers off the ATI website. I find it unlikely that it's a driver problem; why then would it begin at such an unpredictable interval?

[Klaustrophobia]

you never know.  just as an easy check to rule that out, you can uninstall the drivers and run driver sweeper in safe mode, then reinstall.  if problems persist, more than likely your hardware has gone south and it's time to call in the warranty.

[General Battuta]

I rolled back to previous drivers but have had the noir problem at least once since then (though with decreased frequency.) By way of trade, however, I'm getting some hard-locks whenever I try to enter a fullscreen 3D app.

[redsniper]

I fail to see the problem. Enjoy your NoirSpace.

[Fury]

General Battuta, remove the card and use can of pressurized air to clean it up where necessary. Then re-attach it, make sure it is attached to the PCI Express slot properly and the plastic lever snaps in place. Then make sure the external power cord is also properly attached.

If that does not fix the problem, the symptoms hint at failing video card.

[General Battuta]

General Battuta, remove the card and use can of pressurized air to clean it up where necessary. Then re-attach it, make sure it is attached to the PCI Express slot properly and the plastic lever snaps in place. Then make sure the external power cord is also properly attached.

If that does not fix the problem, the symptoms hint at failing video card.

Already done. I even opened the card, re-did the thermal paste, and made sure the heatsink was seated properly. 

Now testing my PC with an 8800 GTS to see if the card is actually the problem.

[Flipside]

If you're using an LCD screen then it sounds like a dodgy connection somewhere in the card, since I think LCD's use a HSB signall, rather than an RGB one, if it's a CRT monitor, I'd say the problem is more likely the monitor

[General Battuta]

I am indeed using an LCD.

[Nuclear1]

I think the battman most make an update

[General Battuta]

I popped in an Nvidia 8800 GTS and installed the drivers for it.

The noir issue is gone, as are the system lockups. Everything works fine, including FreeSpace...except the two modern games I've tried so far (Team Fortress 2 and Bad Company 2) both froze after a few minutes of totally normal, butter-smooth play.

In fact Bad Company 2 went on working, in that I could hear myself walking around and shooting, but the image just froze on the screen and wouldn't update. Alt-Tab and the task manager worked fine.

[Androgeos Exeunt]

Is it a refresh rate issue? I get that on MapleStory sometimes with my CRT monitor.

[General Battuta]

Is it a refresh rate issue? I get that on MapleStory sometimes with my CRT monitor.

...

[Admiral LSD]

If it were an S-Video or component (Y/Pb/Pr or Y/Cb/Cr) connection, I'd say you were losing the colour difference signal(s) and therefore only getting the luminance signal. I honestly can't think of anything (short of software tricks to force the output to greyscale) that would even remotely cause a similar effect in RGB system...

As for the 8800GTS, did you remove every last trace of the ATi drivers with something like the aforementioned driver sweeper (or one of the many other programs that do a similar job) before installing the nVidia ones? There may still be traces of the old drivers lurking around which may be conflicting with the nVidia ones and throwing you off.

[General Battuta]

You're right; it was old ATI driver traces causing those lockups. Fortunately I figgered this out a few days ago and swept them, and everything's been running smooth since.

Guess I need to grab a new card.