Laptop HDMI stops working- suddenly only works on SmartTV and PC monitor - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 16 Old 08-03-2013, 08:45 AM - Thread Starter
Newbie
 
mussgr's Avatar
 
Join Date: Aug 2013
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Hi, biggrin.gif

I'm using a Toshiba Satellite L750 laptop, and the HDMI port stopped working one day. I've tried it on 3 TVs and with 3 different cables and no joy.

However, when plugged to a SmartTV or a computer monitor via HDMI to VGA adapter it works fine.

Could the circuit have partially fried due to hot swapping (my family all use this laptop)? Could a repeater or some other intermediate make it work on our regular TVs?

Many thanks
mussgr is offline  
Sponsored Links
Advertisement
 
post #2 of 16 Old 08-03-2013, 10:04 AM
AVS Special Member
 
budwich's Avatar
 
Join Date: Dec 2002
Location: Kanata, Ontario, Canada
Posts: 1,321
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 21
You have likely changed a setting in your laptop..... why is that??? Because, if your are using an "hdmi to vga adapter CABLE" (ie. with NO external electronics / box) then the actual signal being sent from your computer over the cable is NOT an "normal" hdmi (digital) signal but instead an "transposed" VGA (analog) signal. Check your settings on your output cards / computer interfaces.
budwich is offline  
post #3 of 16 Old 08-03-2013, 05:38 PM - Thread Starter
Newbie
 
mussgr's Avatar
 
Join Date: Aug 2013
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
i don't normally use this- we were running tests with a friend trying to work this out. it's unlikely that a setting has been changed, plus we've looked into the Nvidia panel and did a clean driver install.
mussgr is offline  
post #4 of 16 Old 08-04-2013, 08:08 PM
 
alk3997's Avatar
 
Join Date: Jan 2004
Posts: 3,722
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 87
Quote:
Originally Posted by mussgr View Post

Hi, biggrin.gif
...
However, when plugged to a SmartTV or a computer monitor via HDMI to VGA adapter it works fine.

...

Many thanks

The what? VGA is analog and HDMI is digital. So a very special adapter is needed. What are you using?

I thought that the satellite has both an HDMI and a VGA port?
alk3997 is offline  
post #5 of 16 Old 08-05-2013, 11:40 AM - Thread Starter
Newbie
 
mussgr's Avatar
 
Join Date: Aug 2013
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
the setups were:

1) from hdmi(PC side) > converter to vga > vga monitor

2) Hdmi(Pc side) > hdmi (Smart tv side)

3) Hdmi (pc side) >Regular tv Hdmi <- NOT WORKING

*several regular tvs were tried.
mussgr is offline  
post #6 of 16 Old 08-05-2013, 05:00 PM
AVS Special Member
 
budwich's Avatar
 
Join Date: Dec 2002
Location: Kanata, Ontario, Canada
Posts: 1,321
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 21
Ah...have fun with this one Andy... :-)
budwich is offline  
post #7 of 16 Old 08-06-2013, 08:15 AM
 
alk3997's Avatar
 
Join Date: Jan 2004
Posts: 3,722
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 87
Quote:
Originally Posted by mussgr View Post

the setups were:

1) from hdmi(PC side) > converter to vga > vga monitor

2) Hdmi(Pc side) > hdmi (Smart tv side)

3) Hdmi (pc side) >Regular tv Hdmi <- NOT WORKING

*several regular tvs were tried.

I understand what you are saying you are doing. In item #1 - how are you converting from HDMI (digital) to VGA (analog)?

It would also help if I knew the make and model numbers of all of the components. Also the length of any HDMI cables and whether they are High Speed or Standard Speed cables.

It's not enough information for a question like this to say "regular TV" or "Smart TV". These TVs all have HDMI chipsets and the revision of those chipsets can have a lot to do with compatibility issues. Also the resolution of the TVs versus what the PC can generate can even cause no picture to appear.

So with what little you have provided me, the best I can tell you is that may be normal or it may not be normal.

To directly answer your original questions,

1) Yes, hot swapping can cause an HDMI connection to not work anymore but then I would expect the Smart TV HDMI connection to also not work (unless the problem was on the "Regular TV" side - try another HDMI source to verify that the "Regular TV" HDMI input works).

2) Could a repeater make the "regular TV" work? Very unlikely unless you are currently using a long (greater than 25 foot ) cable and even then it probably would not help.
alk3997 is offline  
post #8 of 16 Old 08-06-2013, 08:17 AM
 
alk3997's Avatar
 
Join Date: Jan 2004
Posts: 3,722
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 87
Quote:
Originally Posted by budwich View Post

Ah...have fun with this one Andy... :-)

If only my psychic abilities were able to determine models numbers and HDMI chipset revisions :-)

I think I could translate the question to, "In one configuration, my HDMI connection is not working. Could you tell me what is wrong?"
alk3997 is offline  
post #9 of 16 Old 08-06-2013, 02:35 PM - Thread Starter
Newbie
 
mussgr's Avatar
 
Join Date: Aug 2013
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
You're right of course. These are the TVs that didn't work:

Sony Bravia kdl-32u2000
Samsung ue32f4000awxxh v3
Philips 32pf9631d/10

And the one that did:

Samsung ue40es6100wxxh

Adapter:http://www.newit.co.uk/shop/HDMI-VGA

Laptop: Toshiba Satellite L750-1LR, Win7.

I'd just like to stress that the setup STOPPED working overnight, it's not that it was never working anyway. We've gone through the typical rounds of upgrading drivers, tried Fn+F5, Winkey+P, and Nvidia's "My monitor doesn't appear".
mussgr is offline  
post #10 of 16 Old 08-06-2013, 03:01 PM
 
alk3997's Avatar
 
Join Date: Jan 2004
Posts: 3,722
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 87
That helps.

The Philips that works allows for the following resolutions (from the owner's manual):
640x480@60Hz ; 800x600@60Hz; 1024x768@60Hz or the video formats 720p and 1080i.

The Sony that stops working allows for:
576i, 480p, 576p, 1080i and 720p

The Sammy 32f4000 works with: 720p (and I couldn't find anything else)

The Sammy ue40es6100 seems to work with 720p, 1080i and 1080p.

Your Toshiba laptop has a native resolution of 1366x768.

So, my guess is the older Philips is able to handle the not-so-standard 1366x768 resolution of the laptop while the rest of the TVs do not.

Here's what I would do: I'd set the laptop resolution to 1280x720 (720p) and hopefully the laptop screen can handle that. I'd then verify I was in clone mode for the external monitor (in other words the external monitor resolution is the same as the built-in LCD). I'd then try the Sony, Samsung and Samsung again to see if 720p works.

That R-Pi adapter is interesting. I doubt it will be on the market for long since it claims to handle HDCP. It is actually much more than a cable.
alk3997 is offline  
post #11 of 16 Old 08-06-2013, 03:49 PM - Thread Starter
Newbie
 
mussgr's Avatar
 
Join Date: Aug 2013
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Slight post screw-up, it was the Philips that also didn't work and second Samsung that did (I made an edit).

I'll try that but I'm confused as to how it would help since the laptop doesn't even recognize a device has been connected, and when it did work no resolutions were changed beforehand. Do you think it'll force the laptop?
mussgr is offline  
post #12 of 16 Old 08-06-2013, 04:28 PM
 
alk3997's Avatar
 
Join Date: Jan 2004
Posts: 3,722
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 87
Quote:
Originally Posted by mussgr View Post

Slight post screw-up, it was the Philips that also didn't work and second Samsung that did (I made an edit).

I'll try that but I'm confused as to how it would help since the laptop doesn't even recognize a device has been connected, and when it did work no resolutions were changed beforehand. Do you think it'll force the laptop?

Of course you realize that you didn't mention that the laptop doesn't even recognize the device?

The change in which panel works, actually makes this easier. The newer panel has the more up-to-date HDCP implementation and allows 1080p.

That you don't get any signal or that the panel isn't even recognized points towards HDCP. If it was an invalid resolution, I would expect an "invalid format" or similar message to appear on the TV.

Trying a different resolution (720p) certainly wouldn't hurt. But, with the new information and clarification, I suspect you are being "copy protected" and that is why it isn't working. But, try a compatible resolution and verify that it isn't that.

The only other thing I can think of is that your HDMI cable can't handle the signal with those TVs. What are you using for an HDMI cable and have you tried a different cable (High Speed HDMI preferably)?
alk3997 is offline  
post #13 of 16 Old 08-06-2013, 05:38 PM - Thread Starter
Newbie
 
mussgr's Avatar
 
Join Date: Aug 2013
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
The cables are high-speed. No more than 2-3m long. I don't really know what HDCP is or how to handle it. Sorry for not clarifying though.

But even so, why would the setup just stop working?
mussgr is offline  
post #14 of 16 Old 08-07-2013, 05:55 AM
 
alk3997's Avatar
 
Join Date: Jan 2004
Posts: 3,722
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 87
Quote:
Originally Posted by mussgr View Post

The cables are high-speed. No more than 2-3m long. I don't really know what HDCP is or how to handle it. Sorry for not clarifying though.

But even so, why would the setup just stop working?

Usually if a setup was working and then stopped it is because of a system board failure or a cable failure or a settings change. The most likely with Windows is a settings change that was made without the user's knowledge. In the case of automatic updates, a new driver can be added which caused previously working items to now no longer work or reset a setting back to its default.

HDMI's HDCP (high definition content protection) is the ability for HDMI to shutdown its signal if it detects tampering on the line. It does this by exchanging keys with the destination device (the sink) - in this case the TV. If the authentication fails, HDMI stops sending any signal. So, if those TVs are no longer working it could be that HDCP no longer "trusts" those TVs and stopped sending a signal.

I have seen where newer (improved?) drivers can cause a previously working device to stop. Can you go back to older drivers and see if that makes a difference? It may be that by updating a driver you caused the units to no longer work.

After that, I suspect you need to start trying difference computer models to see which ones work with the TVs and which do not. Also other sources such as a BluRay player should be tried with each TV to verify that the TVs work with everything else. Once you would get an idea of combinations that work or don't work, you might have a better idea of where the problem lies. Using one computer as a source doesn't provide enough sampling to determine whether the problem is in the computer or the TVs.
alk3997 is offline  
post #15 of 16 Old 08-08-2013, 04:22 AM - Thread Starter
Newbie
 
mussgr's Avatar
 
Join Date: Aug 2013
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
I have seen where newer (improved?) drivers can cause a previously working device to stop. Can you go back to older drivers and see if that makes a difference? It may be that by updating a driver you caused the units to no longer work.

Ι don't know about that. This has happened before to this laptop. Toshiba's service people replaced the motherboard and didn't format.
mussgr is offline  
post #16 of 16 Old 08-08-2013, 05:44 AM
 
alk3997's Avatar
 
Join Date: Jan 2004
Posts: 3,722
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 87
OK. Then that would be a good avenue to try this time.
alk3997 is offline  
Reply HDMI Q&A - The One Connector World

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off