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No display on HDTV through "kanex thunderbolt to HDMI cable", after upgrading to lion.

8602 Views 13 Replies Latest reply: Oct 14, 2012 7:57 AM by LLLe RSS
nikhilmozika Calculating status...
Currently Being Moderated
Aug 20, 2011 8:30 AM

I have a macbook pro 13-inch, Early 2011. My problem is, i am not able to get any kind of output to my samsung hdtv using "kanex thunderbolt to HDMI cable". Everything worked fine when i was on snow leopard but after upgrading to lion it stopped working. I recentlly upgraded to 10.7.1 still no luck.


Whenever i try to connect the cable to the macbook a blue screen flashes for 1 sec & goes away without detecting the HDTV. I have manually tried to detect display but same thing happens. My TV shows "searching for signal" brieflly but then it changs to "no signal" shortlly. I have tried this on multiple samsug tvs at my home all with the same result.


I have gone through the support communities for answers but could find a specific answer, so hope someone could help me.



MacBook Pro, Mac OS X (10.7)
  • kustomuv7bk12 Calculating status...
  • eww Level 9 Level 9 (52,975 points)

    Contact Kanex technical support and ask whether their adapter has been tested with Lion.

  • eww Level 9 Level 9 (52,975 points)

    Apple isn't going to provide support for the Kanex adapter anyway. Call Kanex and explain the situation. Make it clear that you aren't claiming the adapter is defective, because it works fine with your 21" TV; you just want to know how to convince it to talk to your 40" TV.


    Consult the TV's manual to make sure you're connecting to the proper HDMI port on it — there may be one you have to use for a computer connection.

  • myzshbeeb Calculating status...

    I have the same problem. Let me know if you are able to resolve it. My thunderbolt to hdmi connection worked before upgrading to the new OS X Lion software.

  • Mick906 Calculating status...

    I am having the same problem, but I am still on Snow Leopard.  It worked just fine with my Samsung tv until I did the latest Thunderbolt update.  Now I cannot get Video or Audio. 

  • KB from Ontario Level 1 Level 1 (5 points)

    I just acquired the "Kanex Mini DisplayPort to HDMI Cable with Audio Support (10 ft.)" directly from Apple (  It does not function and will NOT send video to the external HDMI screen (at this point I am not concerned about audio).  The external screen is a LG2762D TV.




    I have a MacBook Pro 13" (early 2011, purchased in July 2011) with the current OS 10.7.2.


    I know the mini display port and LG TV both function because I can connect to the TV via the mini display port to DVI adapter on the MacBook and using the DVI input port on the TV.


    When I use the Kanex Mini DisplayPort to HDMI Cable and connect it the HDMI input port of the LG TV (of course first assuring the TV input port, HDMI1 or HDMI2, is set correctly to active on theTV) what happens is the MacBook Pro detects the LG display BUT there is NO IMAGE on the TV and the TV says "No Input Signal" or something to that effect.


    So, the MacBook Pro detects the TV but no display can be seen on the TV.


    I have talked with AppleCare and they tell me the cable is faulty and needs to be replaced.


    I am a reasonably technical person and havea good understanding of troubleshooting and I have come to the same conclusion - that the cable is faulty.


    However, do any experts out there have any comments or recommendations?  Can I expect the replacement cable to work or am I better off with a different product (eg: another mini display port to HDMI adapter together with appropriate HDMI-HDMI cable to get close to the total 10' length of the Kanex)?




    PS: Kanex does not appear to have a phone number so I was only able to submit a support request on-line.  I have not yet received a reply.


    (I cross posted this to

  • Mick906 Level 1 Level 1 (0 points)

    Update:  I emailed Kanex and here is their suggestion:



    I had this cord up and working with Snow Leopard on my Macbook Pro (early 2011).  I had the sound working through the tv.  Then I got the new Thunderbolt update.  Now nothing works at all. No picture, no sound, and no option in the sound .  It only shows the internal speakers.  Any suggestions ?



    Please retry resetting your PRAM and NVRAM. Thank You



    Kanex Mini DisplayPort to HDMI Cable 10 ft (3 m)


    Product Link:


    Thank you,

    Kanex Products


    Now my question is how do you reset the NVRAM and what is it???

  • KB from Ontario Level 1 Level 1 (5 points)

    It's goot kanex got back to you.  I wish they had a support number.  I am still waiting for a reply.


    I tried the resets Kanex suggested with absolutely no positive effect whatsoever - still no display on the TV via the Minidisplay port to HDMI cable..


    For information on what and how see "Resetting your Mac's PRAM and NVRAM".


    Apple's web store product information on this cable gives no indication whatsoever that this device is NOT compatible with the early 2011 MacBook Pro line (this is the model I have) or OS X Lion (which I also have). The Apple website does indicate we check with the Kanex website for warranty information.


    The Kanex website says the device is compatible with the MacBook Pro including the early 2011 model AND the FAQ on the product says "Yes, the MDPHD10FT works great on Mac OS X Lion".


    We Apple customers who purchase products form the Apple store have a reasonable expectation that the products will work together - especially if we talke with Apple Advisors before purchasing - as I did. Hopefully Apple and Kanex work together to make sure that products work harmoniously  - or that if they do not the warnings of incompatability are clear and plain.  I hope we're not getting stuck between companies in a finger pointing exercise.

  • iroiro Calculating status...

    Solved. I have a Dell u2711 and had a similar Problem. Macbook Pro 17" from 2010 with a Logilink male miniDisplayport to female Displayport Adapter. It worked only once and after I reconnected the cable with adapter the display would only turn on and then off again.


    Solved after reading this: ageIndex=3


    Before I reconnect the display to the macbook I pull the power cord from the display. (Actually I just switch off the multi socket power supply). It works like a charm. Every time.

  • Siggy1 Calculating status...

    Video amd Audio Works Great!  I got the MacbookPro 13" mid-year August 2011 (Lion 10.7.3) + Pioneer 42" Plasma or Sony 32" LED + Kanex Thuderbolt to HDMI cable.


    Show "Display" Icon on the Menu Bar.  Select Detect Display from pull-down menu,  Turn on Mirroring. To fine tune, select TV and MacbookPro setting preferences.  Enjoy!

  • lilonders Level 1 Level 1 (0 points)

    What the heck is going on with this?  As has been noted numerous times prior to my post this is an ongoing issue for a brand that sells itself as above all others in computer related hardware.  I will never purchase another Mac as long as I live and thank god I' only made the mistake of buying one game for my MBP.  All my old windows machines (despite their other failings) are able to carry out the simple exercise of recognizing and allowing me to switch between laptop and external displays.  I'm expecting my presentation to go ahead tomorrow in spite of the fact I've had to dust off a dodgy old Acer laptop in order to be able to present on an external display on a faithful and tried and tested HDMI to HDMI cable.  The thunderbolt/mini DVI cable can go back to Apple.


    Maybe this is to be expected when boffins try to reinvent the wheel, but boy do I feel like a massive sucker for buying a name.  Lesson learned.

  • LLLe Calculating status...

    You are part of a growing number of frustrated Mac owners that have discovered, there is a problem with using

    Displayport cable adaptors with the thunderbolt port while using Lion or Mountain Lion. I also purchased a Kanex - Displayport to HDMI (with audio support) from the Apple store after being assured it would definitely function with my Thunderbolt ported Mac as it does with my Displayport Mac (Core 2 Duo). It displays the "desktop" only, I do not have mirroring or any options to activate mirroring. I think it is curious that with the large demand for displaying computer images on TV's that Apple does not sell a Thunderbolt to HDMI cable as they do with Displayport to HDMI.


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