Blue spots on screen

  ChrisP 19:20 10 Jan 2005

My screen picture has a number of symptoms which could be unrelated but which all started at around the same time.

First, I frequently get blue spots (pixel size) - up to 100 or so and often in discontinuous lines - on my CTX TFT screen. These are blue on the desktop (which is black) or on the surrounds to photos (also black). On pictures themselves, the colours of the spots vary with the background colour. These spots disappear when I refresh the screen but often come back later on in the same session, for instance with other photos. I have replaced my screen with another TFT screen and this shows the same effects, so I conclude that it is unlikely that this issue is related to either the screen or its connections.

Second, the screen occasionally, and, with time, more frequently, goes blank for about 2 seconds before returning to the same view as before. This is irritating and I am concerned that this may indicate that something more serious may go wrong in future.

Third, when I reboot, I get the usual message saying that my settings are being saved and then the screen goes blank for a second or so before showing a rectangular box which says "Signal out of range H 55.6kHz V 52.2 Hz" and, on a second line "Mode should be below 1280 x 1024/75Hz". This persists for some time until the picture changes to show the usual blue welcome screen and message that my settings are being loaded. There is no opportunity, for example, to start in Safe Mode or run 'GoBack'. My settings are 1024 x 768, with a refresh rate of 60Hz, this latter controlled by the TFT screen.

When I turn off completely and then re-start, the process is normal and I can access all the usual things, such as BIOS and Safe Mode. The only change is that the screen is littered with random characters in vertical lines. These are up to 100 and sometimes make the words underneath hard to read. If I avoid making any registry changes (not easy over an extended period), then the number of these characters declines and they eventually go away only to reappear when I download updates, etc.

I have Windows XP Home, with 1.5GB RAM, and a 2.1Gz AMD Athlon XP processor. My graphics card is an Nvidia GeForce4 Ti 4200 with AGP8X.

I would be grateful for any comments, and especially help, please.

Many thanks

  Graham ® 19:35 10 Jan 2005

My spots were red! I was sent a replacement monitor.

Try this: when the spots/characters are present, take a screen shot using 'prt scr', paste it into Paint and save.

If the spots are present in the screen shot, it's the graphics. If they're not, it's the screen at fault.

  ChrisP 23:29 10 Jan 2005


As mentioned in my original post, I tried another screen with the same results. But your idea is a good one. I tried that immediately and the spots are still there, so it has to be the graphics. Thanks for the idea.

Do I need a new graphics card? It's only two years old!

  ChrisP 18:42 11 Jan 2005

I have now checked my BIOS settings and reinstalled the latest drivers. I now get normal rebooting without the small notice saying my settings are wrong, but everything else remains the same.

Can the random characters I get on the black screens before XP loads be due to the graphics card or does this have to be something else?

  Djohn 18:48 11 Jan 2005

What size screen is your TFT? I notice you have your settings at 1024x768 and this would be the normal setting for a 15" TFT. If you have a 17" TFT then the resolution should be 1280x1024.

  ChrisP 20:43 11 Jan 2005

It's a 17". Is this a problem? If the icons are a bit small, should I increase the dpi?

  Djohn 04:47 12 Jan 2005

Increasing the resolution to its native setting of 1280x1024 will give a much sharper display but the Icons and text in most applications will be smaller.

I'm not sure if this is the cause of your problem though but it will be worth while trying it out for a few days to see if it makes an improvement.

Yes, you can increase the size of the Icons from your display settings [DPI] to make them larger to compensate for the increase in resolution.

Most of your applications should be fine to use at the higher setting even most web sites will look fine, it is only when you use forums such as this one that you can't increase the text size in your browser if using IE6 [View/text size from the menu bar will not help in forums] but if you use a different browser such as Firefox or similar then increasing the text size from the view menu will work and give you a decent size of text to read without losing any of the quality.

  ChrisP 11:13 12 Jan 2005

Thanks. I'll give this a try. As I use Firefox, text size should'nt be a problem. I would be surprised if the random characters on the 'black' screens before Windows launch are due to this, but the other effects may change. One comment has been that I should re-install after a format but I would really prefer not to have to do this. The last time was less than a year ago and I have quite a bit of software installed, so this would mean a week's work!

  Djohn 14:30 12 Jan 2005

I agree that a format should always be the last choice unless the system is so badly set-up or infected with virus and other nastys that a format would be the quickest route to go.

Stick with this a while longer, I'm sure we'll sort the problem. I remember that prior to SP2 there was a hotfix download from the Microsoft site for Nvidia drivers and if I accepted it I too would suffer the blank out of display for 1-2 seconds at irregular intervals but no spots or random characters.

These blank outs of the display would happen only every two to three days but on removing the Hotfix it cured the problem. Since SP2 I have not had this recur.

  ChrisP 23:09 12 Jan 2005

I have increased the size to 1280 x1024 and am grateful for your suggestion as this is obviously what I should have been using anyway. The number of blue spots on the desktop has increased but only in proportion to the number of pixels. There are probably no more than eight or so at any one time and, as mentioned before, refreshing removes these. When I do any other action and then come back to the desktop, there they are again, just a few and in different places each time. Irritating but not desperate, though!

  Djohn 00:51 13 Jan 2005

Have you tried taking the graphic card out and re-seating it again ChrisP?

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