Re: TV problem - horizontal lines
Captain Infinity
Dennis M wrote:
>Does anyone have an idea why very faint horizontal lines, spaced about 7 or
>8 inches apart and about a quarter of an inch thick, would move slowly up
>the TV screen after a DVD is played? One of the lines is slightly darker,
>followed by a line that's slightly lighter. After a while they eventually
>go away but I'm wondering what causes this. The same problem has happened
>on two different TV's so I don't think it's a defect in the set (or the DVD
>player).
You're describing a problem that usually has to do with the presence of a
magnetic field near the CRT. Move your machines farther apart.
**
Captain Infinity
Scott Dorsey
>Does anyone have an idea why very faint horizontal lines, spaced about 7 or
>8 inches apart and about a quarter of an inch thick, would move slowly up
>the TV screen after a DVD is played? One of the lines is slightly darker,
>followed by a line that's slightly lighter. After a while they eventually
>go away but I'm wondering what causes this. The same problem has happened
>on two different TV's so I don't think it's a defect in the set (or the DVD
>player).
Sounds like RFI to me.
This is rec.audio.pro. We only do audio here. Throw your TV set away and
get better speakers. TV will rot your brain. Listen to more music instead.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Captain Infinity
Scott Dorsey wrote:
>This is rec.audio.pro. We only do audio here. Throw your TV set away and
>get better speakers. TV will rot your brain. Listen to more music instead.
Music? Bah! You kids and your....music. Music is pap. The only things
worth listening to are audiobooks and Old Time Radio shows.
**
Captain Infinity
Mac Breck
> This is rec.audio.pro.
Would asking about how to make high quality WAV, MP3 or MIDI files from
a DVD source be On-Topic, there?
--
Mac Breck (KoshN)
-------------------------------
"The Dresden Files" (2007)
Harry Dresden: [re. Bianca] What is it about bad girls? They lie,
cheat, won't suck your blood even when you beg them to, and for some
reason, no matter how badly they treat us, we still can't walk away.
Mark
> Does anyone have an idea why very faint horizontal lines, spaced about 7 or
> 8 inches apart and about a quarter of an inch thick, would move slowly up
> the TV screen after a DVD is played? One of the lines is slightly darker,
> followed by a line that's slightly lighter. After a while they eventually
> go away but I'm wondering what causes this. The same problem has happened
> on two different TV's so I don't think it's a defect in the set (or the DVD
> player).
horizontal bars that move slowly vertically are "hum" bars... they are
60 or 120 Hz interference and the TV frame vertical sync rate is 59.94
Hz. I have no idea why you are getting hum bars.
Mark
Richard Crowley
> Does anyone have an idea why very faint horizontal lines,
> spaced about 7 or 8 inches apart and about a quarter of
> an inch thick, would move slowly up the TV screen after
> a DVD is played? One of the lines is slightly darker, followed
> by a line that's slightly lighter. After a while they eventually
> go away but I'm wondering what causes this. The same
> problem has happened on two different TV's so I don't think
> it's a defect in the set (or the DVD player).
"7 or 8 inches apart" gives us little to go on when we don't
know what the reference is? (the size of the screen)
In any case, it sounds like typical case of "hum bars".
It is the visual equivalent of mains hum interference
in audio. Assuming that you are in North America or
someplace where NTSC is used. Because NTSC has
a vertical rate of 29.97Hz vs. the mains frequenty of
30Hz. If any power line 30Hz leaks into the video,
it causes a hum-bar that takes ~10 seconds to roll
up the screen.
Here is what I would do as a differential diagnosis:
Unplug everything from the TV (except the power!)
Turn on the TV (from cold, like in the morning
after being powered off all night). Watch for the
hum bars as the TV warms up. (Give it a couple
of hours.) If you see hum bars at any point, then
there is a problem with the TV, if not, then the
problem is likely somewhere in the source (DVD
player, etc.) It is not unknown to have things like
this to develop after "warming up".
Captain Infinity
Mark wrote:
I went to a hum bar once. None of the working girls there had any teeth.
It was a pretty good time. No idea why I never went back.
**
Captain Infinity
Anim8rFSK
den...@dennmac.net (Dennis M) wrote:
> Does anyone have an idea why very faint horizontal lines, spaced about 7 or
> 8 inches apart and about a quarter of an inch thick, would move slowly up
> the TV screen after a DVD is played? One of the lines is slightly darker,
> followed by a line that's slightly lighter. After a while they eventually
> go away but I'm wondering what causes this. The same problem has happened
> on two different TV's so I don't think it's a defect in the set (or the DVD
> player).
Macrovision did that with VHS. Usually with DVD Macrovision will just
kill the picture completely, but it's possible you're borderline.
You're still watching the DVD player as a source when this happens?
Did this happen on 2 different TVs and 2 different DVD players? If
that's the case, do they have a common signal source like cable?
--
Star Trek 09:
No Shat, No Show.
http://www.disneysub.com/board/noshat.jpg
Alan F
> Does anyone have an idea why very faint horizontal lines, spaced about 7 or
> 8 inches apart and about a quarter of an inch thick, would move slowly up
> the TV screen after a DVD is played? One of the lines is slightly darker,
> followed by a line that's slightly lighter. After a while they eventually
> go away but I'm wondering what causes this. The same problem has happened
> on two different TV's so I don't think it's a defect in the set (or the DVD
> player).
These are the classic symptom of a ground loop problem. Some component
in your setup - TV, STB, DVD player, sound receiver, co-axial cable line
- is not properly grounded. You are seeing an effect of a 60 Hz cycle
pickup somewhere in the system from something not grounded to the same
reference ground as everything else.
Are all of your A/V devices connected to the same power strip or surge
protector? If not, that can be the cause. However, for people who have
cable (or satellite) TV, the most common cause is a ungrounded or poorly
grounded co-axial cable line. Disconnect the co-axial cable line from
the STB/DVR and see if the faint horizontal lines go away. If they do
and you have access to the external cable box at the service area, check
the grounding wire. A short term solution that sometimes work if your
surge protector has RF passthrough connectors is to run the co-axial
cable line through the surge protector. Depending on the design, that
can ground the RF cable line.
However if you have a ungrounded co-axial cable TV line, you should be
able to ask for a service call to fix the problem. Just don't expect the
customer service representative to have a clue as to why you need a
service call.
If all else fails, you can get a Jensen VRD-1FF Isolation Transformer
for the cable line. But they cost around $60.
Alan F
Taylor
Don't listen to Scott. Donate it to a thrift store like Goodwill, The
Salvation Army, Value Village/Savers and/or Talize. And buy yourself a
preemo flatscreen LCD or plasma model. You can get a 42" for $1000 (C)
at Wal-Mart.
And just think... you'll be ready for the Feb. 2009 U.S cut off date
for analog OTA broadcast signals and 2011 for Canada.
Romeo Rondeau
You mean the TV was broken on the Karaoke machine?
Hugh
And if you're listening to C-rap, that's not music, not even close.
Hugh
You sure it wasn't a hummer bar.
Bishoop
"Richard Crowley" <rcro...@xp7rt.net> wrote in message
news:-4ydnUNy3fHFjpXVnZ2dnUVZ_u2dnZ2d@pcez...
30 Hz mains frequency?
Richard Crowley
> 30 Hz mains frequency?
Bzzzzzt! (or perhaps, "hmmmmm" :-)
Yes, of course, 60Hz mains freq in N.America.
But hum bars, nevertheless.
May or may not have anything to do with ground
loops, etc. Could just as easily be power supply
filtering, SCR dimmer interference, etc. etc.
Tomi Holger Engdahl
> Does anyone have an idea why very faint horizontal lines, spaced about 7 or
> 8 inches apart and about a quarter of an inch thick, would move slowly up
> the TV screen after a DVD is played? One of the lines is slightly darker,
> followed by a line that's slightly lighter. After a while they eventually
> go away but I'm wondering what causes this. The same problem has happened
> on two different TV's so I don't think it's a defect in the set (or the DVD
> player).
One possible reason for this kind if problems are ground loops.
More information on ground loops can be found at
http://www.epanorama.net/documents/groundloop/index.html
Other potential problems:
- magnetic interference nearby coupling to cable or devices
- bad electrical power filtering on equipment (for example
capacitors on power supply going bad on old TV)
--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/
Arny Krueger
news:dennmac-ya0240800...@NNTP.InfoAve.Net
> Does anyone have an idea why very faint horizontal lines,
> spaced about 7 or 8 inches apart and about a quarter of
> an inch thick, would move slowly up the TV screen after a
> DVD is played? One of the lines is slightly darker,
> followed by a line that's slightly lighter. After a while
> they eventually go away but I'm wondering what causes
> this. The same problem has happened on two different TV's
> so I don't think it's a defect in the set (or the DVD
> player).
When powerline hum is mixed with the video, the resulting contaminated video
can have this problem.
If the recording is off-the-air particularly from a cable channel, the
source of the problem can be cross-modulation in the tuner section of the
DVR.
remys...@yahoo.com
> 8 inches apart and about a quarter of an inch thick, would move slowly up
> the TV screen after a DVD is played?
If it's not interference, the macrovision theory works if you are
playing your DVD player through the VCR, usually because you're out of
video inputs or needing to convert to an RF input.
Kimba W Lion
>If it's not interference, the macrovision theory works if you are
>playing your DVD player through the VCR, usually because you're out of
>video inputs or needing to convert to an RF input.
I've never heard of Macrovision producing this symptom no matter what you do
with the encoded signal.
trotsky
It can also be people communicating from the afterlife.
Anim8rFSK
And I've had it happen, in my office, because we were looping through.
Mr Ed
(29.97) of a second resulting in 60hz hum slowly climbing the screen. It
could be a result of poor filtering, maybe a bad capacitor in the set, or a
synchronous motor nearby.
--
Mr Ed
http://www.ed-camin.com
http://home.earthlink.net/~bcamin/betty.htm
http://www.mountairykiwanis.org
http://www.ma-artleague.org
http://home.earthlink.net/~j3dogs/index.htm
http://home.earthlink.net/~donnahayes/index.htm
"Bishoop" <no...@nowhere.none> wrote in message
news:u_udnRtMk7uzpZXV...@giganews.com...
Richard Crowley
Agree. That is NOT a symptom of Macrovision.
It is most likely hum bars. Several possible causes,
but Macrovision is NOT one of them.
Nancy2
wrote:
I have to regularly twitch or move the cables on my satellite box, or
move the box farther away, to get rid of faint, wide bands of snow
that move slowly up the screen. It's usually too much equipment too
close together.
N.
vdub...@earthlink.net
change. Stop ruining it with facts.
Kimba W Lion
>And I've had it happen, in my office, because we were looping through.
Ground looping, you mean.
remys...@yahoo.com
> And I've had it happen, in my office, because we were looping through.
I've seen on Cold Mountain and There's Something About Mary DVDs
played through a VCR, although it's more of a slightly scrambled porn
effect.
phil-new...@ipal.net
| 30 Hz mains frequency?
Or some multiple thereof, such as 60, 90, 120, 150 Hz, etc.
--
|WARNING: Due to extreme spam, I no longer see any articles originating from |
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pj
> Thanks to everyone for the knowledgeable replies (especially Richard, Alan,
> Tomi, Arny & Nancy). I will experiment with the grounding of all the
> components and see if that helps.
>
> Also my apologies for the rec.audio.pro crosspost (but hey, you guys
> apparently got some good laughs out of it!)
One thing you might also look for is a bad surge
supressor on one of the devices.
--
pj
Anim8rFSK
Kimba W Lion <kimbawlion@> wrote:
No. Only happened on macrovisioned 3/4 UMatic tapes. We made the
company start giving us unmacrovisioned tapes, and the problem stopped.
Alan
>On Apr 17, 9:40=A0pm, denn...@dennmac.net (Dennis M) wrote:
>> Does anyone have an idea why very faint horizontal lines, spaced about 7 o=
>r
>> 8 inches apart and about a quarter of an inch thick, would move slowly up
>> the TV screen after a DVD is played? One of the lines is slightly darker,
>> followed by a line that's slightly lighter. After a while they eventually
>> go away but I'm wondering what causes this. The same problem has happened
>D
>> player).
>
>horizontal bars that move slowly vertically are "hum" bars... they are
>60 or 120 Hz interference and the TV frame vertical sync rate is 59.94
>Hz. I have no idea why you are getting hum bars.
Since they are there after playing a DVD, and go away, I bet they
go away about the time the DVD player times out and powers off.
If so, that might be a clue . . .
Alan
L Alpert
> Once Upon A Time,
>
>> This is rec.audio.pro. We only do audio here. Throw your TV set
>> away and get better speakers. TV will rot your brain. Listen to
>> more music instead.
>
> Music? Bah! You kids and your....music. Music is pap. The only
> things worth listening to are audiobooks and Old Time Radio shows.
>
>
>
> **
> Captain Infinity
What's wrong with a few hours of gentle rap music?