About 6 minutes after bootup, the image on my monitor starts to deteriorate. First the cursor gets an unnatural shadow. Then several vertical bars snap across the screen, at precisely spaced intervals, the full height of the screen. Within these bars the image appears to "crawl".
Switched out the monitor, same effect.
When the system is allowed to cool off, it reboots with a normal image.
Opened the box and checked the fans. I have three: power supply, graphics board, and processor. All three spin, but the box has been very dirty. I vaccumed it. We have a renovaton project going in the room where the computer sits, so it has been sucking dust.
The problem came on suddenly a few days ago, but it is now a permanent feature. After six minutes, the display produces these columns or bars of visual noise. Since it seems to be a heat effect, I then turn the machine off.
The system is a 3-year old Dell Dimension 8250. The supply is a 250 W HP-P2507F3C.
Anyone seen this effect before?
Possible this is hum? Blown electrolytic capacitor maybe? Or should I look at the motherboard or graphics?
Many thanks for your insights.
More about :vertical bars display power supply problem
I would check the graphics, what kind of chip is it.. and is it passively cooled? If so it could be over heating and try leaving the case open and have some air flow on the chip. I've encountered problems like this before on my Radeon 9700pro and Voodoo2s in SLI where in games textures disappear.. random lines.. or lines appear to be extremely large.
Hi. I swapped the 9700 for an ati card in our other Dell (a 7500, probably).
So far, after 28 minutes of continuous operation, no vertical bars have appeared.
I will keep testig, but it looks just now as though it will turn out that the 9700 graphics card was responsible. I think maybe it overheated, fan and all, because of the heavy dust in here lately (sanding and painting and general uproar.)
You are lucky; this same thing happened to my friend's computer, only he was on vacation when the fan died. Consequently I had to give him my old Ti4200. Some sort of new cooling for the 9700 should be pretty cheap.