Hello,

The display on my Gateway VX930 monitor has suddenly gone bad: vertical streaks now appear across the screen. This happened overnight and I haven't changed hardware or updated software recently. I have display problems both under my Linux and windows partitions (under windows the computer will only boot in safe mode and complains about a drawing problem). I was able to temporarily restore the display to normal by rebooting several times, but it went back to vertical streaks again within a couple of hours.

My question is this: before I go and spend a lot of money on new hardware, is there a way to test whether the problem is with the graphics card, the monitor, or something else? Unfortunately, I don't have an extra monitor I could swap with the current one as a check.

I would greatly appreciate any suggestions you might have. Many thanks in advance.

What kind of streaks are these exactly?

Are they solid colour bars, noise or something else?

Also, what graphis card do you have?

If there are any other artifacts such as an unstable picture, flicker or image distortion then this could be the monitor having trouble handling the sychronisation signals being applied. Although I doubt this is the case. This kind of trouble is to do with the values in your xf86config.

Try switching resolutions using Ctrl+Alt+KP+ and KP- and see if the problem persists. Does bashing the monitor (not too hard) change things?

A more likely cause is the graphics card as you suspect, if windoze complains about it too.

The only other case similar to this I had to fix was when the graphics card (well, everything) was dirty - the owner was a smoker, and over the months the insides of his box got covered in tar. Tar being slightly condictive messed things up a bit, and the graphics card being especially sensitive to such things produced a colourfully scrambled display. If your card is visibly dirty then try cleaning it with a soft cloth and some circuit board cleaning fluid - places like radio shack sell this stuff, else tape-head cleaner (aka isopropyl alcohol) should be alright. But remember to wear a static strap!

Hope this helps...

Thank you PsychosisNode for your suggestions.

I followed your advice and cleaned the card. I also tried hitting the monitor a bit. In the end I was able to rule out everything but the graphics card. Eventually, things got so bad that the text during the boot process was barely readable because individual characters were replaced with other, random characters (clearly not something a bad monitor would do). And the computer would freeze when it got to the splash screen.

I went out and bought an ATI Radeon 9200 to replace the NVIDIA Geforce4 4200 ti I was using. Unfortunately, I couldn't get the ATI driver I downloaded for this card to install properly due to a library-file conflict, but the generic VESA driver I'm using now seems to work fine.

In other words, I'm back to normal operation. Thanks again