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Composite video from Compaq Armada e500 to Panasonic LCD TV TC-20LA1.

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Peter

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Apr 7, 2011, 1:42:34 PM4/7/11
to
Folk,

This is an arcane question of application rather than repair but I
don't know of a better place to ask.

I've connected the composite video output from a Compaq Armada e500
running Debian Squeeze, to a Panasonic LCD TV TC-20LA1. The display
on the TV works for the COMPAQ logo, the BIOS, and the console
startup messages. When X takes over, the TV appears to lose sync.
Nothing helpful is evident in the BIOS of the Armada.

The Armada was donated without the original software. I'll guess
that there was software designed to drive the composite video output,
independently of the laptop screen.

I'm thinking of trying this in /etc/X11/xorg.conf.
Section "Monitor"
...
VertRefresh 60.0
EndSection

Can a setting in xorg.conf harm the laptop hardware? Any advice or
comments or instructions to get a display on the TV suitable for
watching a movie?

Thanks, ... Peter E.

mike

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Apr 7, 2011, 9:13:19 PM4/7/11
to
try messing with the screen resolution.
You need both V and H frequencies to be correct.
The lapotp may not be able to do both at the same time.
Or you may be able to use the function key that controls
the internal/external display switching to blank the lcd
and make it work.

hrho...@att.net

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Apr 8, 2011, 3:22:47 PM4/8/11
to

Have you looked at the output from the Armada with an oscilloscope???

David Nebenzahl

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Apr 8, 2011, 3:38:50 PM4/8/11
to
On 4/8/2011 12:22 PM hrho...@att.net spake thus:

> Have you looked at the output from the Armada with an oscilloscope???

And just how would you propose to interpret those results?


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mike

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Apr 8, 2011, 5:33:06 PM4/8/11
to
David Nebenzahl wrote:
> On 4/8/2011 12:22 PM hrho...@att.net spake thus:
>
>> On Apr 7, 12:42 pm, Peter <peasth...@shaw.ca> wrote:
>>
>>> This is an arcane question of application rather than repair but I
>>> don't know of a better place to ask.
>>>
>>> I've connected the composite video output from a Compaq Armada e500
>>> running Debian Squeeze, to a Panasonic LCD TV TC-20LA1. The
>>> display on the TV works for the COMPAQ logo, the BIOS, and the
>>> console startup messages. When X takes over, the TV appears to lose
>>> sync. Nothing helpful is evident in the BIOS of the Armada.
>>>
>>> The Armada was donated without the original software. I'll guess that
>>> there was software designed to drive the composite video
>>> output, independently of the laptop screen.

If there was, it wouldn't help you with linux.
I'd post the question in a linux group.

>>>
>>> I'm thinking of trying this in /etc/X11/xorg.conf. Section
>>> "Monitor" ... VertRefresh 60.0 EndSection
>>>
>>> Can a setting in xorg.conf harm the laptop hardware? Any advice or
>>> comments or instructions to get a display on the TV suitable for
>>> watching a movie?
>>
>> Have you looked at the output from the Armada with an oscilloscope???
>
> And just how would you propose to interpret those results?
>
>

If it were me, I'd google
http://www.google.com/search?num=100&hl=en&lr=&safe=off&q=ntsc+waveform&aq=0&aqi=g1g-v2g-b1&aql=&oq=ntsc+wave

But it might be effective to just compare the waveform while booting
when it does work
to the wavefrom after booting when it doesn't work.

I don't think the problem is interpretation. The problem is CONTROL
under linux.

Adrian C

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Apr 9, 2011, 8:16:05 AM4/9/11
to
On 07/04/2011 18:42, Peter wrote:
> Folk,
>
> This is an arcane question of application rather than repair but I
> don't know of a better place to ask.
>
> I've connected the composite video output from a Compaq Armada e500
> running Debian Squeeze, to a Panasonic LCD TV TC-20LA1. The display
> on the TV works for the COMPAQ logo, the BIOS, and the console
> startup messages. When X takes over, the TV appears to lose sync.
> Nothing helpful is evident in the BIOS of the Armada.

My foolproof method for sorting out something like this will make linux
aficionados freak out in disgust, but here goes....

1. Temporaily install a Microsoft GUI operating system (Win95..Windows
7) including relevant driver software for the graphics card.

2. Attempt to get a decent picture on your TV with the above driver

3. Install powerstrip trial
http://entechtaiwan.com/util/ps.shtm

4. Make tweaks as necessary using powerstrip

Then go here

<http://www.x.org/wiki/FAQVideoModes#ObtainingmodelinesfromWindowsprogramPowerStrip>

--
Adrian C

TomC

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Apr 9, 2011, 9:19:05 AM4/9/11
to
Try changing the refresh rate or the display driver for the screen display.
Seems like the OS is loading something that the tv doesn't understand.

Peter <peas...@shaw.ca> wrote in news:9498e99f-253d-464e-8876-
e77629...@r13g2000yqk.googlegroups.com:

Peter

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Apr 14, 2011, 11:44:16 AM4/14/11
to
On Apr 9, 6:19 am, TomC <x...@xxx.com> wrote:
> Try changing the refresh rate or the display driver for the screen display.  
> Seems like the OS is loading something that the tv doesn't understand.

With this in /etc/X11/xorg.conf the refresh rate is still 94 Hz.

Section "Monitor"
...
VertRefresh 60.0
EndSection

Can VertRefresh be set on the laptop display; is it wired to 94 Hz?

I'll check with the scope as suggested by hrhofmann and mike and if
necessary resort to the method of Adrian C.

Thanks to everyone, ... Peter E.
peasthope at shaw.ca

Peter

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May 3, 2011, 5:42:26 PM5/3/11
to
On Apr 8, 2:33 pm, mike <spam...@gmail.com> wrote:
> But it might be effective to just compare the waveform while booting
> when it does work
> to the wavefrom after booting when it doesn't work.

There are now two photos from the screen of the storage scope on a
server.
http://members.shaw.ca/peasthope/BiosDisplay.jpg is the signal from
the BIOS display.
http://members.shaw.ca/peasthope/XdmDisplay.jpg is the signal from
XDM.
Just to recapitulate, the BIOS display is visible on the Panasonic TV.
The XDM display is not; as if not syncing. I've never checked a
composite
signal. Do these photos give any ideas?

By the way, I connected the scope lead to the center pin of the
composite
connector. Did not connect the shield of the scope lead and did not
connect
the shield of the composite connector. What is the best way to
connect a
scope to composite video? In case it helps, this scope can subtract
two signals.

Thanks, ... Peter E.

Jeroni Paul

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May 5, 2011, 4:48:02 PM5/5/11
to
On 3 mayo, 23:42, Peter <peasth...@shaw.ca> wrote:
> On Apr 8, 2:33 pm, mike <spam...@gmail.com> wrote:
>
> > But it might be effective to just compare the waveform while booting
> > when it does work
> > to the wavefrom after booting when it doesn't work.
>
> There are now two photos from the screen of the storage scope on a
> server.http://members.shaw.ca/peasthope/BiosDisplay.jpgis the signal from
> the BIOS display.http://members.shaw.ca/peasthope/XdmDisplay.jpgis the signal from

> XDM.
> Just to recapitulate, the BIOS display is visible on the Panasonic TV.
> The XDM display is not; as if not syncing.  I've never checked a
> composite
> signal.  Do these photos give any ideas?
>
> By the way, I connected the scope lead to the center pin of the
> composite
> connector.  Did not connect the shield of the scope lead and did not
> connect
> the shield of the composite connector.  What is the best way to
> connect a
> scope to composite video?  In case it helps, this scope can subtract
> two signals.
>
> Thanks,                                 ... Peter E.

You must connect the shields, the waveforms on the scope are all
noise.

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