Strange HDMI connection problem - please HELP!


Captain Jack Sparrow

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This is a really bizzare one which has left even me bamboozled.

I have three devices which I would like to connect to my TV (obviously not all at once) via HDMI. They are...
  • BlackBerry Z10 (Micro HDMI)
  • BlackBerry PlayBook (Micro HDMI)
  • iPhone 4S (regular HDMI)
The TV is an LG 42LG7000. Its HDMI inputs support HDCP.

Before I begin, it's important to note that all of these devices support two different HDMI output modes. They are...
  • Phone display mirroring (mirrors exactly what's visible on the phone's screen to the HDMI connected display)
  • Video output (media is displayed at its native resolution on the HDMI connected display. The phone can be used as normal, without affecting the media currently showing on the HDMI connected display)

I initially thought that the HDMI port on my BlackBerry Z10 was faulty as this was the first device that I experienced the issue with. I was considering sending the device to BlackBerry for a repair. However, further testing has revealed that the HDMI port may not be problem.

On the TV, I noticed that my Z10 would fail to maintain a consistent HDMI connection with the TV. Wiggling the cable would sometimes re-establish the connection, only for the connection to fail again after a matter of seconds. Attempting to use the video output mode resulted in an instant HDMI connection failure. So naturally, I tried a different cable and got the same results. I then tried a different HDMI port on the TV, but the results remained the same.

Next, I tried the same thing with my BlackBerry PlayBook. The results were the same.

Finally, I tried my iPhone 4S which uses regular HDMI. You guessed it, the results were the same again!
So, at this point, I ruled out faulty HDMI ports and poor quality HDMI cables.

The only other HDMI capable device I have is the HDMI interface in my car. This is designed to mirror a smartphone screen to the car's reverse camera monitor and route HDMI audio through the vehicle's stereo system. This HDMI input also supports HDCP.

I performed the same tests using the car's HDMI interface and here are the results...
  • The BlackBerry Z10 worked correctly with both the screen mirroring and video output modes. Wiggling the HDMI cable did not cause the HDMI connection to be lost.
  • The BlackBerry PlayBook worked correctly with both the screen mirroring and video output modes. Wiggling the HDMI cable did not cause the HDMI connection to be lost.
  • The iPhone 4S was problematic. It worked correctly only with the screen mirroring mode. Wiggling the HDMI cable did not cause the HDMI connection to be lost.
    Video output mode only worked for a few seconds. After that, HDMI connection was lost, but then immediately re-established in screen mirroring mode. This interrupts any media that was being displayed. On the iPhone 4S, it isn't possible to display media in screen mirroring mode, as the device automatically switches to video output mode, which of course, results in the problem mentioned above.
I'm inclined to believe that it's most likely the TV which is causing this problem, but the inconsistent iPhone behavior observed in the car is blowing me off course.

Does anybody have any ideas?

Apologies for such a long post, but I want to make sure that I haven't missed any vital information.
Please help me. Don't let my 1080p ship sink.

Thanks

- Capt. Jack Sparrow.
 
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Ian

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I'd agree that it sounds like a problem with the TV, primarily as it seems unlikely that it could be multiple phones or cables failing. I think the iPhone 4S/Car issue is secondary to this one.

I don't really know how you could go about fixing this, if it is an issue with the TV. Are there many configurable options for HDMI inputs (i.e. can you disable CEC and anything else via the TV options menu)?

You could also try updating the TV firmware - LG provide firmware downloads and it looks like they last released firmware in 2013 (at least for UK models) : http://www.lg.com/uk/support/support-product/lg-42LG7000
 

Captain Jack Sparrow

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Thanks Ian,

I have just checked the TV and the firmware version is 3.49.00, so no updating is necessary.
Not sure what you mean by CEC or 'anything else'. As far as I can see, unless I'm blind, there are no HDMI settings present in the menu.

I am going to try connecting a laptop through the HDMI port later, although the Sky HD box is already connected to a HDMI port, so it's strange as to why the same issue doesn't occur here.

- Capt. Jack Sparrow.
 
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Ian

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I've just checked on my TV, as we've got the 47LG7000 which I guess is almost identical - I can't see any HDMI config options either :(. On the other TV (Sony), we have quite a few HDMI config options - but that's quite few years newer.
 

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