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From: lyberty
Date: Dec. 2004;
last updated: March 8, 2005
ATI Radeon 9800 Pro TV-OUT problem : Electrical Interference -- research
and troubleshooting page
Keywords / Problem Summary:
ATI Video Card S-video out (also, and TV to PC connection, out or in):
powerline noise, banding, TV out image, diagonal lines, ati radeon svideo,
noise s-video, video out interference-like hum coming from my TV, the
picture has lines that move up across the screen, electrical interference
(interferance), electrical noise
Description:
I have a Dell XPS (gen 2) with an ATI Radeon 9800 Pro.
It comes with an S-Video out, with the implied functionality of hooking
it up to your tv.
But when I hook it up to my tv (Sony Trinitron*, NTSC format), the
picture quality is fine,
but there is a large band moving from the bottom to the top of screen;
and diagonal (almost horizontal) small (ghost-like) lines moving from
left to right.
These are coming from some kind of elecetrical interference; these
lines are OVER the image
on the screen, and even appear when the TV out is disabled (using
ATI control panel).
It does not matter if the image is sent as the standard 680x480 resolution
@ 54 or 60 Hz*; I tried many resolution and Hz settings with no effect.
[Update: a new S-video cable changed it so that when TV out was disabled,
interferance disappeared. See "So what did you try?" section
below.]
Note that when I hook up my older PC (with a smaller power
supply, and an NVIDIA based-graphics card) to the tv using the
same (original) S-Video cable, there is no interference.
*Note: NTSC (North American television format)
televisions display at 60Hz (actually 59.94Hz).
Searching around online hasn't been that helpful; but there does seem
to be a recurring theme: this problem seems to happen with ATI Radeon
cards a lot. There are some claims like "it
is not a card's fault; there's some grounding problem / noise problem
with the PC, or the cables." But then you see some people claiming
that replacing the card with another brand fixed the problem.
There's a lot of talk about "you need better grounding" but
how the hell do you Ground the PCI card? Or reground the power supply?
This doesn't seem to be explained anywhere. (Use "comments",
below, if you know how to ground a PCI card.)
So if it's poor motherboard design, or PC power supply design, or Graphics
Card design, there's really no excuse for it:
peripheral devices like DVD players, VCRs, PVRs (TiVo) etc. don't have
this problem.
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"From: "stodge"
Newsgroups: alt.comp.periphs.videocards.ati
Subject: 9200se TV Out problem...diagonal lines on screen
I am using a Radeon 9200se and the TV out image has diagonal lines all
over
it. Does anyone know how to get rid of the lines?...because they basically
make TV out feature completely useless. I am using S-Video connection.
any help appreciated"
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On a Dell b-board: " I have my TV connected to my Inspiron 4000
to watch DVDs. But when the AC plug is connected there is an interference-like
hum coming from my TV, and the picture has lines that move up across
the screen. When I disconnect the AC and run the computer on battery
all this goes away."
"Same thing happens with my i8100, I would also like to know the
answer to this one. "
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The discussion "Powerline
noise in captured video" talks about a similar problem, but
the consensus is that the users
house just wasn't grounded properly. I don't think this is the problem
though:
- if it's a general grounding problem, why doesn't the DVD create that
electrical noise when connecting the same S-video cable from
the DVD to the television? [Update: tried hooking up my older PC with
an NVIDIA card with an S-Video out: no interference at all.
So it's not a general electrical or grounding problem with my house.]
The closest
thing to a potential solution I've heard:
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From the pictures it looks like a ground loop i.e. signal feedback through
the ground system.
Try this, go to the store and get a three wire plug tester. Test the
outlets that you use to power you system. If you are using a surge protector/power
strip test each outlet. Fix the problems as indicated.
Some motherboards are more sensitive then others.
Carefully check the PVR (tv-in / tv-capture) board for broken caps
or loose wires.
Make sure that the mounting plate is tight to the board and screwed
tight to the computer.
____________________________________________________________________
You can read a definition of a "ground loop"
here. But the short answer is "A ground loop occurs when there is
more than one ground connection path between two pieces of equipment."
Another person states "I've got round the problem by changing
to a graphics card with VIVO.
(see topic RADEON VIVO) and viewing via a VCR. "
Common Replies to User Complaints About the Interference (Audio
or Video) Caused by the PC:
- try new wires (insulated, etc.) or try running wires "parallel"
- Rip up your house wiring, take apart your wall plug, have a ground
wire put on your wall plug, etc.
- It's a grounding problem (produces hum/static)
- It's a Ground Loop
- Make sure your card is seated firmly (PCI or AGP card pushed in all
the way)
But again, I ask the question: why do I need to mess around with
wiring, etc. if a DVD player, or Tivo, etc can handle being plugged
into the same outlet as your PC and be connected to your tv via an S-Video
cable?
Most likely answer: just poor engineering on the part of the PC
manufacturer (or Video Card manufacturer).
I just think there's electrical interference bleeding into and through
the Video card, through the S-video cable, to the tv.
Note that when I hook up my older PC to the tv using the same S-Video
cable, in the exact same arrangement (same location, plugs, etc.) there
is no interference.
So wouldn't a better question be: how can one better ground a PC power
supply, or better ground the Video Card itself?
If a "ground loop" problem, this actually sounds intriquing:
"Go to Radio Shack and get a Hum Eliminator. "
From Radio Shack: "Ground
Loop Isolator -- Helps eliminate electrical noise and hum caused
by ground loops. -- $17.00"
However, this item consists only of audio cables; so it's not
going to help with the video problems.
They also have something called a "Plug-In
Noise Filter" ($40), maybe I could plug the television into
that??
Note that the manual
provided by ATI has no useful information, and I could not find
anything useful on the Dell tech support site
(also sent Dell a support request email, which was never responded to).
So what did you try?
1. Tried updating Radeon video drivers.
Result: No effect.
2. Tried playing around with the video settings in the Windows
and ATI control panels.
Result: No effect
(Note that it does not matter if the image is set as the standard 680x480
resolution @ 54 or 60 Hz; I tried many resolution and Hz settings with
no effect.)
3. Tried using an S-Video to standard (base-band, a.k.a. RCA
video) Signal
Converter. (from Radio Shack)
Result: Still getting interferance: Large band moving from bottom to
top of screen; diagonal (almost horizontal) small lines moving from
left to right.
4. Tried plugging the television into different sockets around
the house (just in case there was some problem with having the PC and
TV plugged into the same wall socket).
Result: No effect. Still have same problem.
5. Bought what was supposed to be a high-end S-Video cable with
better shielding.
Result: I actually had some good results with this. The diagonal
(ghost) lines actually disappeared, but I still had the bottom-to-top
banding/interference (lines slowly crawling up screen).
Also, when the TV-out connection was disabled, the lines/interference
disappeared. So now I only get the interference when the PC card is
actually
sending a signal.
Since I used a shielded cable, and better shielding is supposed to better
prevent outside electrical interference, part of the problem was, apparently,
outside interference.
(Again, why this would happen for PC, but not for DVD player, is unknown.)
Resources: I don't remember what I paid for
my new cable, but I refused to buy the overpriced one offered by Monster
Cable.
If you're interested though, they claim their expensive "THX-certified
Super Video cable" has
" Extreme rejection of radio frequency (RFI) and electromagnetic
(EMI) interference—high-density double shielding ".
(Just remember that maybe 50% of the price of Monstor Cables pays
for hype)
6. Tried reseating the Video card and checking cable connections.
(No screws to tighten as my Dell PC uses a plastic connector.)
Result: No effect.
7.. Waiting on a new DVI-D to composite converter from ATI
so I don't have to use the S-Video out...
[Update: Jan. 2005] So I got the DVI-D
to COMPONENT (RGB) adapter (converter): $30. Picked up some
component cables too (another $10). There is still a very slight "banding"
going up the screen, but it's so slight you have to really look for
it. But this solution didn't really work out,
because for whatever reason, the ATI controls can't seem to get the
whole monitor image to appear on the tv screen. Even at the smallest
setting
[640x480].
[Update: Jan. 13 ,2005: Apple is releasing
an adapter (the "Apple
DVI to Video Adapter") that connects DVI to either component
OR S-video. And
for only $20.
This is Apple, which is notorious for overpricing items. WHAT EXCUSE
DOES THE PC MARKET HAVE FOR NOT PRODUCING A COMPERABLY PRICED ITEM?
Check out, for example, this overpriced ($75.00 as of Jan 2005)
PC
to TV converter (though it does come with a choice of Composite
Video, S-Video or YPbPr (Component) outputs, and the cables are built
in...)
$75? YOU CAN BUY A FRICKEN VIDEO
CARD WITH TV OUT (S-Video) FOR $30! ]
CONCLUSION: NOTHING BUT NVIDIA FROM HERE ON OUT.
The control program offered by nVidia is much better too.!
[Update: August 2005] Interestingly, if
I route the new (insulated) S-Video cable I got to my S-Video compatible
VCR first (then S-Video out to tv from vcr), there are no visible interference
lines AND I can use the ATI control program to resize the image on the
television...)
--------
Quote from board; Topic: S-Video
Cable ATI to TV: Moving Bands
"I use S-video on my ATI 8500 and had the same problem, I found
out the compression happens when the card resizes your desktop to the
s-video resolution of 640x480. If you set your desktop to 640x480 then
it looks fine, as good as my DVD player with component input (on Toshiba
36" tube TV anyway). The downside is that a 640 desktop bites because
your DVD controls are massive and most windows don't even fit on the
screen. Using less colors at 800x600 seems to help a little but going
to 640 is the only way to get a perfect picture with "TV out"
--------
View Equipment
=LINKS=
COMMENTS? :
*Sony FD Trinitron WEGA KV-27FS120 27 in. Direct View Flat Screen SDTV
Television:
Interesingly enough, the plug on the Sony tv is only two prong (does
not have third grounding prong).
But I think this is typical for televisions...
======================DISPLAY ADAPTER INFORMATION======================
Graphics Card Manufacturer = ATI Technologies Inc.
Graphics Chipset (ASIC) = RADEON 9800 PRO
Device ID = 4e48
Vendor ID = 1002
Subsystem ID = 1002
Subsystem Vendor ID = 1002
Bus Type = AGP
Current Bus Settings = AGP 8X
Primary Display Device = Yes
BIOS P/N = 113-A07517-100
BIOS Version = 008.004
BIOS Date = 2003/05/06
Memory Size = 128 MB
Memory Type = DDR SGRAM / SDRAM
Tuner Type = Not Detected
Decoder Type = ImpacTV2+
Video Standard = NTSC
Audio Type = Not Detected
Display Drivers Version = 8.082-041130a-019577C-ATI
Display 2D Version = 6.14.10.6497
Display D3D Version = 6.14.10.277
Open GL Version = 6.14.10.4776
Control Panel Version = 6.14.10.5134
Graphics Card Manufacturer = ATI Technologies Inc.
Graphics Chipset (ASIC) = RADEON 9800 PRO Secondary
Device ID = 4e68
Vendor ID = 1002
Subsystem ID = 1003
Subsystem Vendor ID = 1002
Bus Type = PCI
Current Bus Settings = Not Detected
Primary Display Device = No
BIOS P/N = Not Detected
BIOS Version = Not Detected
BIOS Date = Not Detected
Memory Size = Not Detected
Memory Type = Not Detected
Tuner Type = Not Detected
Decoder Type = Not Detected
Video Standard = Not Detected
Audio Type = Not Detected
Display Drivers Version = 8.082-041130a-019577C-ATI
Display 2D Version = 6.14.10.6497
Display D3D Version = 6.14.10.277
Open GL Version = 6.14.10.4776
Control Panel Version = 6.14.10.5134
Discussion of connecting PC to Television
And the ATI controls don't let you resize or move the screen if you're
using Y Pb Pr (composite) for some reason (they do for the s-video/tv
out).
And they only allow 30, 60, 72, or 75 hertz (and above) settings, for
some reason.
I tried playing around with the hertz and resolution, and the dongles,
but that didn't help either:
(There are "dongles" on the DVI adapter that let you set your
ouput to 480 interlaced, 480 progressive, 540 progressive, etc.)
Ok, so standard NTSC video is 525 lines of horizontal resolution, with
480 of those being visible, with interlaced scan [525/60 aka 480i].
But that doesn't mean you have to limit the output to that, right?
DVD is supposed
to output 720x480, 704x480 or 352x480: so the tv (at 480 lines horizontal
resolution) should be able to support a higher resolution height...
But the manual doesn't state the maximum supported display. I wonder
what it is.
And is it better to select interlaced or progressive in the controls
for optimal viewing on the tv?
I would guess that my tv doesn't support progressive scan content....
=LINKS=
COMMENTS? :
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