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Old August 29th 13, 02:32 PM posted to alt.comp.periphs.videocards.nvidia
Paul
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Posts: 13,364
Default DVI on TV no signal

PcGAmeR22 wrote:
Greetings Paul and thanks for the reply
as I mentioned the tv is not HDMI compatible , there are no HDMI jacks
on the tv therefore I cannot connect it through an hdmi cable , the
cable is too short anyways
I only have a DVI jack on the back of the tv that I plugged my video
card to , but nothing popped up on the screen


I don't know if this is going to help, but...

1) I assume the TV is DVI-D and "just digital". If so,
that's the best option for the card at the moment.
That should work.

2) You can experiment with utilities.

In this picture, on the right is Moninfo
( http://www.entechtaiwan.com/util/moninfo.shtm )
Currently, it shows only one entry as "real time".
That means, it has detected one device on the serial
interface on the video card port. It is not detecting
a second monitor. So only one EDID inside a monitor,
can be seen by Moninfo.

http://imageshack.us/a/img689/4167/whh2.gif

Also on my sample Imageshack picture, is the Display
control panel.

So this was my experiment.

1) System normally has one monitor.
2) I connected a second monitor connector. I have a "dongle"
which just has termination resistors on it. The purpose
of such a resistor is to cause the video card "detection"
to be triggered. This is not a real monitor, just a portion
of the electrical interface. Enough to fool it into thinking
a second monitor is connected.
3) When I go to Display control panel in Windows 8.1, the
"new monitor is not detected". I assume that means no signal
is being sent to it. Even though the termination resistors
are present. I must click the "Detect" button, before the
second monitor is detected. My dongle device has no EDID chip,
so resolution info is not available.
4) Once "Detect" is clicked, the Display control panel selects
1024x768 as a safe resolution value. If it was a real monitor,
there would be a picture on it now. It seemed the desktop
went into Span mode immediately. (This is on Win 8.1 Preview).
5) The display on Moninfo doesn't change during all of this.
Even if Moninfo "Refresh" option is used. This tells me,
the "real time" option on Moninfo, only detects things with
an actual EDID. My dongle has no EDID. There are boxes you
can buy with fake EDID, but I didn't bother with this
option as part of my test items. If I want an EDID, I can
plug in an actual second monitor.

You can use Moninfo, to see if the EDID of the TV is present.
You can try the Display panel "Detect" function, if available.
Maybe the terminations on the TV will be detected that way
(i.e. if the automatic hardware detection isn't working).

It's possible some info is not reaching the computer.

1) EDID not present (serial info that says what resolutions
are supported by the TV).
2) Termination resistors (present in the TV set) are not
detected. This is unlikely.
3) Some handshake, like HDCP, is failing. I don't know of
a utility that gives this info. I haven't a clue how you
monitor it.
4) Driver is determined not to allow a second monitor
to detect. This will take a ton of experiments to bypass,
if true. Like, trying an older driver if available. Or
trying more port combos. Personally, I would expect the
DVI connectors to work, and I'd test them first.
5) Hardware could be broken. That seems unlikely. Between
the Display control panel and Moninfo, if they appear to
be working as intended, you might be more inclined to
suspect this.

When I've heard of troubles, it was usually with a monitor
via HDMI and a computer video card. DVI should be a bit better.

HTH,
Paul