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

Apr 07, 2011 9 Replies

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.


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.

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

On 4/8/2011 12:22 PM snipped-for-privacy@att.net spake thus:

And just how would you propose to interpret those results?

The current state of literacy in our advanced civilization: yo wassup nuttin wan2 hang k where here k l8tr by - from Usenet (what's *that*?)

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

If it were me, I'd google

formatting link

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.

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.
  1. Attempt to get a decent picture on your TV with the above driver
  2. Install powerstrip trial
    formatting link
  3. Make tweaks as necessary using powerstrip

Then go here

Adrian C

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 wrote in news:9498e99f-253d-464e-8876- snipped-for-privacy@r13g2000yqk.googlegroups.com:

y. =A0

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

There are now two photos from the screen of the storage scope on a server.

formatting link
is the signal from the BIOS display.
formatting link
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.

gnal from

.. Peter E.

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

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