TV Picture Qualtity Question

[PacManFan]

Hey everyone,

I've got a 27" TV in my cab with a composite input being run by an ATI 7500 series with TV output.

Overall, the picture looks fairly good, however, there are diagonal lines that go from the upper right to the bottom left. It is very noticable on vertical lines in programs (especially with the color red). Is this caused by interlacing? Can I get rid of it?

I have tried changing the monitor setting in Win98 to be "TV", but all this seems to do is restrict me to using 640x480.

Does anyone know of the correct ATI settings to use for best picture quality?

-PacManFan

[lightspeed]

Hmmm.   This is definitley not normal.   Are you using a Built by ATI card, or a 3rd party card based on the Radeon chipset?  I have a 7200 series going to a TV, and have not noticed anything like that.  

[PacManFan]

It 's a real ATI 7500, When I say diagonal lines, I mean interruptions  in the vertical lines. It's really happening everywhere. It's not noticable on blocks of solid color, except around the edges.

[RandyT]

It 's a real ATI 7500, When I say diagonal lines, I mean interruptions  in the vertical lines. It's really happening everywhere. It's not noticable on blocks of solid color, except around the edges.

You're going to have to try to explain the problem better .

From what you describe, it could be a herringbone interference patter, dot-crawl, bad video memory or over-clocking issues.

Is the problem constantly moving?  What direction? Only on some colors? etc...

The first step in problem solving is proper identification .

RandyT

[PacManFan]

The lines are not moving, they are in a fixed position on the screen. It is more noticable on some of the lower resolutions (640x480)
I'm not overclocking,
I had this problem with a previous ATI video card as well (same TV).
It's happening with all colors, and the interruption pattern goes from upper right to lower left, looks like every other scan-line.

Whats a herringbone interference pattern?
I think this might be caused by interlaced / noninterlaced issues.(But how do I fix?)
-PacManFan

It 's a real ATI 7500, When I say diagonal lines, I mean interruptions  in the vertical lines. It's really happening everywhere. It's not noticable on blocks of solid color, except around the edges.

You're going to have to try to explain the problem better .

From what you describe, it could be a herringbone interference patter, dot-crawl, bad video memory or over-clocking issues.

Is the problem constantly moving?  What direction? Only on some colors? etc...

The first step in problem solving is proper identification .

RandyT

[RandyT]

I might be wrong here, but it's starting to sound like a re-trace pattern.  How old is the TV?  Do you have a different TV to test your card with?

On a black background, are the lines visible and medium to light gray in color?

RandyT

[PacManFan]

It's a fairly new TV, it's a Toshiba, it's cable-ready. It looks sort of like this on a picture. Imagine if you can this pattern of color interruptions overlaid on an image:

/ / / / / / / / / / / / /
 / / / / / / / / / / / /
/ / / / / / / / / / / / /
 / / / / / / / / / / / /
/ / / / / / / / / / / / /
 / / / / / / / / / / / /
/ / / / / / / / / / / / /


No, I don't have another TV to test with (not easily anyways).
No, a black background looks solid, except around the edges.

-PacManFan

I might be wrong here, but it's starting to sound like a re-trace pattern.  How old is the TV?  Do you have a different TV to test your card with?

On a black background, are the lines visible and medium to light gray in color?

RandyT

[Magnet_Eye]

what version of mame are you using? what are video settings?

I had a similar problem, and it was just settings that didn't work together in mame.

maybe not your problem..but who knows?

-m

[toyguy]

I may be way off here, but isn't there an option or two within MAME itself to synchronize refresh and such?  Perhaps trying some of those settings might help.  I run a 27" Toshiba also, using S-video, and except for some pincushioning on bright white screens, it looks great.

[visciouslymamed]

I have the same problem (picture is very good, but there seem to be non-moving ghost lines running from lower left to upper right, most noticable in certain colors). I have an ATI 7000 (built by ATI). I have tried everything I can in the video settings (had almost no effect) and played with many drivers (better, but they are still there), but I can't seem to get rid of these lines.

Has anyone tried the new Radeons with the component output? Any opinions on these?

PacManFan, what model is your Toshiba? I have a 32" Cinema Series Toshiba. btw, I'm using S-Video.

I also have a Rage Fury Pro and it doesn't have this problem on my TV. It can only do 800x600 max and the 3D is pretty slow (for PC games) so I upgraded to the Radeon and now I can't stand bright colors. I tweaked the TV settings and used different drivers, now it's not to noticable execept in large patches of reds, yellows, and white. I try to avoid using these colors.

I don't think it is the TV as it doesn't do this with any other source (including the Rage Fury). I don't have another TV to try it on.
I guess I just need to either save for a new card or drop the Rage Fury back in there.

[Bill_S]

I might be wrong here, but it's starting to sound like a re-trace pattern.  How old is the TV?  Do you have a different TV to test your card with?

On a black background, are the lines visible and medium to light gray in color?

RandyT

I've been fighting just what you describe Randy.  Is there anything I can do to fix a re-trace problem (without buying a new TV)?

[RandyT]

I've been fighting just what you describe Randy.  Is there anything I can do to fix a re-trace problem (without buying a new TV)?

You can try adjusting the HV and focus controls on the flyback (carefully!!).  This might help, or it might not.  Usually this is seen on older sets and I've been told it could be due to dried out capacitors or other component wear.

On the other problem, I'm stumped.  It sounds like a scaling problem either in the drivers or the hardware.

If there is an "image sharpening" option either on the set or the card, turn it off and see if there is any difference.  This tends to add noise at the edges to make an image appear sharper and may be part of the problem.

The composite video signal probably isn't helping much either.  If you have Svideo, then you should be using it.  But if not, composite is better than nothing.


RandyT

[Bill_S]

How do I adjust the HV and focus controls on the flyback (carefully!!).  I don't know what that means?
Are these controls inside the TV?
I'm not afraid of opening the set if someone can tell me what to look for to adjust.  I just love turning knobs!

[RandyT]

How do I adjust the HV and focus controls on the flyback (carefully!!).  I don't know what that means?
Are these controls inside the TV?
I'm not afraid of opening the set if someone can tell me what to look for to adjust.  I just love turning knobs!

The flyback is usually located in the right-rear of the set if viewed from the back.  It's also labeled with access holes on many sets.  The controls are usually one over the other and located directly on the flyback (a large black plastic-looking thing with a thick wire coming out of the top and leading to the CRT.)

But when I say carefully, I mean for YOUR sake.  The flyback is the source of the high-voltage and you need to use caution.  Also, don't just go sticking a screwdriver in just any hole in the back of the set.

Might be a good idea to get a knowledgable friend to help or just take it to be serviced.  Messing with monitors without knowing what you are doing can kill you  .

RandyT