Monitor seems a bit fuzzy

[Densun]

I just got a Hitachi CM615 (17" CRT, 16.1" viewable, .24mm horizontal dot pitch, .23mm horizontal mask pitch, non-glare surface, 1024x768x16x75MHz) and I updated the drivers for it. But the picture seems a bit fuzzy in some places; I'm not sure if it's the screens edges or certain colors. Anyone familiar with this problem?

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[Densun]

I did a test to see where the fuzziness was, and it seems to be just on the left and right edges, and is not with certain colors only. A rought estimate of how far the fuzziness extends is a fifth of the screen on both sides. It gets weaker towards the center. Maybe the phosphors are bleading?

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[Guest]

Hi
Has the monitor always had this problem?
If it has it could be a faulty monitor the fuzzyness could be defoucusing near the edges (usually worse in the corners) or it could be poor convergence. To see if its convergence look closly at the fuzzy bits and see if you can see whether characters or lines have colour fringing around them. So you might see a black line with red fringing to the left and blue fringing to the right, if you have this it is convergence error. This happens when the red green and blue electron beams that energise the phosphor on the screen dont converge correctly on their respective phophors, the electron beam not only lights up its own phophor but also lights up the phosphor beside it creating a coloured fringe.
This is usually a limitation of the tube and is one of the reasons why expensive monitors look better than cheaper ones. If you do see this fault make sure that you hae no manetic fields around your monitor like speakers phones etc then degauss your monitor and see if the picture has improved. To degauss your monitor either use the manual degauss on the monitor if it has one or switch the monitor off for an hour or two then switch it back on again.

If you did not see and convergence error the it could be poor focus this will be manifested as thick blurry lines with very little or no colour fringing. if this is the case it sounds like the dynamic focusing criciut not working properly, this circuit varies the focus voltage as the electron beam scans the screen so keeping good focus across the screen. If this circiut was not present then you would either get good focus at the center or the sides. The reson for this is because the electron beam coms from a point at the base of the tube and as it scans across the screen it follows an arc, the tube face will be much flatter than this arc and so the distance from the guns in the tube base to the sides and corners will be greater than the distance to the centre of the screen. So to focus the electron beam at the sides requres a different focus voltage than foucussing in the centre.
In both cases it is most likely a fault with the monitor although some monitors do have some user adjustments for convergence which may help if you have a convergence problem.
Without actually seeing the fault it it difficult to suggest what is wrong maybe if you could take a fairly hi-res photo which shows the problem I might be able to tie it down better for you.
Maybe you could get the monitor checked out from where you bought it from.
Hope this helps some.
Later
MAD1

 

[Densun]

It might be a convergence problem. When I look at the last pixel column on the left and right side of the screen, I get a different color then what it should be. The left is different from the right. In the area near the left and right edges, the pixels are kind of blurry. It seems like I can make out phosphors more easily there then in the middle.

I just got the monitor, and it has not been used before. It was cheap, so it might be normal for this monitor. I ordered the monitor from an online store (outpost.com), and if I read the return policy correctly, I can't return it anymore becase I have used it. I might be able to send it to Hitachi for replacing or fixing.

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<A HREF="http://www.geocities.com/TimesSquare/Battlefield/1189" target="_new">Byte Size Games</A><P ID="edit"><FONT SIZE=-1><EM>Edited by Densun on 12/27/00 05:25 PM.</EM></FONT></P>

 

[JoeHead]

definately sounds like convergence. Cheaper monitors are more suseptable. Hell you still have the main 99% of the screen.

<b> Fragg at will!!! </b>

 

[Guest]

Hi
I would have thought that if the monitor was faulty then the supplier would replace/repair it (Thats the situation in the uk) But you may have to pay the transport costs. But as you say it was a cheap monitor so the performance wont be as good as a more expensive monitor but should still be watchable, try compairing it to other monitors of a simillar price at a local store. If the performance of yours is much worse than these you may well have a faulty monitor.
You could try contacting the supplier and asking for advice on their returns policy.

Unfortunately in some cases cheap is not always better and this is why it is very difficult buying something like a monitor, which you have never seen before, very dodgy because you dont know how it will perform until you receive it.
Good luck
Later
MAD1