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Conflict with Thunderbolt/Mini DisplayPort and Sony Bravia Sync

I'm UK-based and I've just bought a new iMac and it's thrown up a bizarre conflict/compatibility problem with my TV.


My 2007 iMac was hooked up to an HDMI input on my Sony Bravia TV (KDL-40Z4500) and used it as a 'second' display, mainly so I could watch the BBC iPlayer and other video, plus iTunes/Front Row. It was connected with a "Mini DVI to HDMI female & DVI-D female Splitter" adapter - using HDMI to get to the TV and a standard 3.5 audio jack to connect the audio (headphone out on the iMac to an input on the TV.


Aside from plugging and unplugging the audio, it worked a treat.


This week I set up my new iMac, which of course doesn't have a Mini DVI port. So the old adapter is no good, and I have now bought two new ones - Thunderbolt (actually Mini DisplayPort) to HDMI - and tried them both. And they both create the same problem.


The picture reaches the TV and can be watched. That much is fine. I no longer have to mess about with an audio jack, either - just change the Audio Out setting in the Volume menu bar option.


But: as soon as the connection is made - iMac to TV via Thunderbolt/HDMI - a conflict occurs with the TV set-up. I have a Sony Home Theatre System for surround sound - HT-IS100 - which is connected to both a DVD recorder and Blue-ray player. (Again, both Sony.) With all these devices being the same brand I can use Bravia Sync. The main benefit being that when I press play on a player, of change a TV channel, both the screen and the system audio switch to that device. No messing around with the remote changing the inputs on both each time you switch.


That is, until you plug in the Mac connection.


This never happened with the old set-up, the old Mac, but now when the connection is made the TV 'forgets' the surround system. The Bravia Sync for it is cancelled and playing anything requires a manual change of channel. (For picture only. The Surround system DOES change over to the playing DVD, say; but the picture doesn't. Though when I change TV channel it doesn't communicate that change to the theatre system, so the picture changes but the sound stays wherever it was.)


According to the menus on the Bravia, it can no longer 'see' the surround system - it only sees the Blu-ray and DVD devices (which are only connected THROUGH that system - all into the theatre device and then back to the TV). The first thing to happen is that the TV switches back to internal sound, its built-in speakers; to get surround back I have to go into the menus and manually change it back.


What seems to be happening is that the connection to the Mac is bringing data to the TV that is overriding the Bravia Sync system's awareness of its home theatre connection. I have to disconnect the Mac HDMI and switch off/on to get the TV and system back to normal. (That's with the second adapter. With the first, the change was permanent enough that I had to do a factory reset each time!)


Given that the TV system is unchanged, and there's no setting anywhere to 'ignore/override' or any other such thing that I can see, I'm pretty sure this comes down to something on the iMac/Thunderbolt/Mini DisplayPort adapter side. The obvious thought, to me at least, being that the inclusion of sound in this set-up, via the HDMI, might be relevant.


As a side note: It's impossible to change the display settings - including sound output - until the second screen is connected to the Mac. This makes total sense, but means I can't change any audio out settings until the connection is made...by which time the Bravia Sync is already 'broken'. Though there isn't much to change, so far as I can see when I am hooked up, that would affect the issue.


I know this is a messy, cross-system problem, but any advice/solutions would be hugely appreciated.

iMac, Mac OS X (10.6.7)

Posted on May 27, 2011 5:16 AM

Reply
28 replies

Feb 26, 2013 8:34 AM in response to Sorking

Found a solution!


On your adapter or cable, simply remove or cover pin #13 which carries the HDMI CEC signals; see http://en.wikipedia.org/wiki/HDMI for the pinout.


I did it on my mDP to HDMI cable (which has a plug, not a receptacle, so the pinout is mirrored of course), was a bit of work, but I got the pin removed, and now everything is shiny.


As an alternative, connect an HDMI to DVI adapter to your adapter, then a DVI to HDMI cable to it (so the chain of connections/conversions is mDP-HDMI-DVI-HDMI), that will remove the CEC signals (because DVI can't do that), but keep the audio intact.

Mar 25, 2013 4:28 AM in response to Sorking

Having this exact same problem...really annoying.


All I wanted was to be able to 'plug and play' and here I am...searching the internet for obscure threads on random incompatibility issues. So much for the 'just works' philosophy.


I've just noticed that according to the HDMI 1.4 spec, that officially supports ARC - if I get an adaptor that supports 1.4 spec will it solve this? The one I have now is 1.3b, I think.

Mar 25, 2013 4:35 AM in response to Wombert

Yeah, I think I will, thanks. This is currently the adaptor I have now though so I'm not sure how exactly to get to the pin easily: http://www.amazon.co.uk/Proxima-Direct®-Mini-Displayport-adapter/dp/B005J0XB7A/r ef=sr_1_1?ie=UTF8&qid=1364211277&sr=8-1


I've just noticed that according to the HDMI 1.4 spec, that officially supports ARC - if I get an adaptor that supports 1.4 spec will it solve this? The one I have now is 1.3b, I think.


Thanks for the (blazingly) quick reply!

Mar 25, 2013 4:54 AM in response to Pemberton_

In that case, removing the pin might be difficult, but you could try coating it with nail polish or something. I guess the easier way though is "ruining" a normal HDMI cable; it took me a little but I ultimately succeeded in removing the pin.


Once again the reminder though, if you have a cable (male plug, not female receptacle) then the pinout (http://en.wikipedia.org/wiki/File:HDMI_Connector_Pinout.svg) is mirrored, so you'll want to remove the fourth pin from the right on the cable.


It's a bit difficult even with small tweezers; what I ended up doing was, using a needle, removing the little "bridge" at the top that holds the end of the pin in place, bending the pin down, and then simply wiggling it left and right inside the connector a few dozen times until eventually, the metal broke at the far end inside the plug. Be careful not to ruin the other pins (they're quite durable though so don't hesitate to be a little bit brutal).

Mar 25, 2013 10:22 AM in response to Wombert

Wombert, this sounds like a terrific hack.


I'm loathe to mark the question as solved, though. It's a brutal thing to damage equipment to get it to work - a hack not a full-blown fix. It's a flaw in what's been made and sold, rather than a missed option in a menu somewhere. This remains an issue Apple should be fixing at (what I imagine is) a software level.


Still, as I say, terrific hack!

Mar 25, 2013 10:26 AM in response to Sorking

Yeah, I agree, they're somehow sending garbage commands over Thunderbolt and that causes the issues.


I have, in the meantime, confirmed that it happens with other brand TVs too, and also when using a 15" Retina MBP, which still exhibits the issue. It might ultimately be a fundamental Thunderbolt incompatibility of some sort, but who knows...


For those who'd rather not damage their cables, there is always http://www.pulse-eight.com/store/products/110-cec-less-hdmi-cable.aspx although that, as I said, requires a separate HDMI extension cable (plus an mDP-HDMI adapter), so it's likely a lot more pricey than one or two AmazonBasics HDMI cables 😉

Mar 25, 2013 6:44 PM in response to Wombert

Guys, thanks for the resolution on this. If I get the cable referenced in the post above would my proposed solution below work (or would I need additional cables)?


I currently have an HDMI cable attached to my Tv. And also have the HDMI to thunderbolt adaptor. Could I purchase the cable mentioned in the above post and also a female to female HDMi connector and get it running.


Basically my existing HDMI cable to the female adaptor, female adaptor to cable in post above, then cable in post above to HDMi to thunderbolt adaptor to MacBook Pro?


Thanks.

Sep 29, 2016 1:52 AM in response to Wombert

Wombert my friend.... Wombert m y f r i e n d!


Haaaaa... I'm just ecstatic right now to have my sound working properly after following your advise. I've spend about 8 hours trying to fix this between two days and I was going mental.


I did exactly as you said (after ruining the wrong pin on my first try - lol) and it worked wonders.


Thank you so much man!

Conflict with Thunderbolt/Mini DisplayPort and Sony Bravia Sync

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