[mythtv-users] No Display: Was sent as "Digest, Vol 95, Issue 26"

[R. G. Newbury]

Top posting fixed:

> On Feb 7, 2011, at 10:29 PM, Newbury wrote:
>
> You have never directly said whether you can boot to a login screen or to the desktop. This makes it difficult to diagnose.If you turn off auto-login and autostart of mythfromtend, what happens?
> It is also possible that your hdmi cable is not correct. Have you tried a different cable and the various inputs?
> There is absolutely no reason why your box should not talk to an LG tv. I seriously doubt that LG *removed* that capability since mine was made. So it *is* operator error of some sort. And we don't know enough to figure it out. What IS your output from the card? DVI, or hdmi? Do you have component or composite or Svideo outputs from the card?
> Need more info. Geoff


On 02/08/2011 09:13 AM, Andy wrote:
 >
 > I'm sorry Geoff,So the answer is 'no' I cannot see the desktop if I 
stop mythfrontend from starting at login.  I can see the splash screen 
when the computer boots up (it says, "ACER" and tells you to push 'Del' 
to enter setup), but as soon as it is done booting (i.e. when the 
desktop is displayed), the TV registers 'No Display'.  That happens 
whether or not I am auto logging into mythfrontend, and it resolves 
itself when I play any clip with audio whether or not it is from the 
desktop or from mythfrontend.

 > In regards to the HDMI cable, I have tried 2 different cables.  One 
of them is confirmed to be an HDMI 1.3 compliant cable.  I have tried 
all 4 HDMI inputs available on the TV.  They all act the same: No 
Display until there is an audio and video signal.

 > My output from the HTPC is HDMI.  I have a DVI output available from 
the HTPC, but not hooked up because I liked the idea of 1 cable for 
audio and video instead of having to split it up.  I have not tried 
hooking it up through a DVI cable.  There is no other output available 
from the video card.

 > I should also mention that the LG TV I'm having problems with is 
model number 37LE5300.  I do have another LG TV, the 55LH90.  The HTPC 
works perfectly when I hook it up to the 55LH90 (i.e. I can see the 
mythfrontend screen), it also works perfectly when I hook it up to my 19 
inch LCD Samsung or my 25 inch LCD Sharp.  I have been hooking it up to 
those other TVs through the HDMI cable.

 > Since it works so well, with no hiccups with EVERY other TV I have in 
the house, I can only guess its a TV problem not an operator error.

WOW. That *IS* weird. Clearly a tv problem and not directly a mythbox 
error.

I have only seen the 'No Signal' error on the TV when the mythbox has 
gone into a sleep state.

I have this in the rc.local of my desktop and I think it is the same on 
the mythbox:

/usr/bin/xset s noblank
/usr/bin/xset s noexpose
/usr/bin/xset s off
/usr/bin/xset +dpms
/usr/bin/xset -display :0.0 q

Offhand, I'm not sure that the last line does anything useful before X 
has started and rc.local runs before that spot.

Those lines take care of any sleep state, but your box should not BE in 
any such state at that point.....Weird......



I can only suggest 3 things to be tried in order:
1) Try a DVI to HDMI adapter so you are using the other output. That is 
actually what I am using on the output of my 
(I-don't-remember-exactly-what) 9500GT card.
2) Break down and use the DVI output together with an audio cable. This 
would be the same as #1 plus the cable.
3) Go pound on the counter at the place you bought the TV!! If you 
bought it at a 'big-box' store such as BestBuy you should be able to 
bully someone into actually pushing your problem to someone who can 
help.  Even the Geek Squad!  (Or the Nerd Herd...you might get Chuck!)

Hmm, on reflection there may be one other thing you can try. It appears 
that you need to 'prime' the audio system before the TV will react.

Try adding the following to your /etc/rc.d/rc.local file:

/usr/bin/amixer set Master 80%
/usr/bin/amixer set Speaker on
/usr/bin/amixer set PCM 95%
/usr/bin/aplay /usr/share/sounds/alsa/Front_Center.wav

The last line is to actually play something which you 
can/should/might/could hear.

Geoff







              R. Geoffrey Newbury