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  • jag Level 1 Level 1 (25 points)

    Add me to the list:  My 23" ACD HD is exhibiting the "black display & LED short-long-short blink pattern" following a brief power outage last night.  Drats!


    Covering ground pins from the power brick makes me nervous, despite its apparently unanimous success for others.  Looks like I'm in the market for an A1098 Apple cinema display power adapter 150W.  Hopefully I can find one.


    Aerodame, are you still contemplating repair service for this failure?  I need a solution, but can't afford a replacement monitor right now.


    What a bummer!  Although reading this thread and the workarounds here has been very helpful...  Thanks to all who've posted previously.





  • Aerodame Level 1 Level 1 (0 points)

    Yes, I did elect to have Apple repair my monitor.  I was a bit dismayed that they did not ship it to the repair center promptly due to the special packaging they said they needed to protect it.  But I weighed different options and although 400 is probably double what would be charged for a non-apple monitor, this is the ideal monitor for my daughters dorm and plug and play with her MACBOOK. So i'm hoping this repairs will actually replace the faulty components with higher quality parts.


    I will be immediately raising the roof with apple care if I have any repeat problems with this expensive fix.


    I would however call apple care and let them know this is a persistent problem.  The more of us that call in the better.


    Good luck!

  • mjfisher Level 1 Level 1 (0 points)

    Hello. I've just been reading through this whole thread, as my 23" Cinema HD Display has gone dead. I would love to try the "Jacobean Fix," but it seems that's for a different model. My Cinema HD Display doesn't have a connector like the one in his photo and video. There's a DVI cord going to a box called a "DVI-ADC Adaptor," and then that box plugs into the wall and also into the CPU. Any advice on which pin I could cover on the DVI connection to get the same result? I should mention that I have no morse-code blinking. When you touch the power button on the Display, it just lights up for a second and goes dead.


    Thanks for any help you can provide.

  • hexdiy Level 1 Level 1 (60 points)

    @ jag:

    although not mentioned in my last post, "Jacobean's fix" does not disconnect any ground at all: the middle pins of the 2 rows of 5 are mere sense lines, most probably joined in the power brick by a mere resistor, thus telling the monitor which type of power brick is attached to it (crude method, it could have been done via I2C, Philips chip to chip protocol, implemented already in the nineties in a.o. VGA monitor sense lines).

    Anyhow, the monitor is well- and -safely grounded via USB and FireWire cable screen to the computer's mains ground as well, if you should worry!

    The 150W brick probably does not carry a pulldown resistor at all, in all probability thence its success in resuscitating the 20" and 23" models. Feel free to use it, circuits will only draw the power they need and its voltage specs are up to par. Also read:

  • hexdiy Level 1 Level 1 (60 points)

    @ mjfisher: sorry to say, but could you just post your ACD model Nr?  You may find yourself in the wrong thread.

  • jag Level 1 Level 1 (25 points)

    @hexdly:  Thanks for sharing your technical knowledge.  You've bolstered my confidence enough that I just may try to obstruct the sense lines! 



  • hexdiy Level 1 Level 1 (60 points)

    @ jag: Go for it! And let us all know how it went. I for one would like to know what is going on with these 20" and 23" monitors, and how come we hear so little amiss with the 30"es. The power bricks? The sense lines? Most probably a POORLY DIMENSIONED 3.3V power regulating chip within the monitors themselves. (See my link earkier in this thread)

    Signing off for now, out here in Europe it is already fairly late, and work to do tomorrow.

  • mjfisher Level 1 Level 1 (0 points)

    Not sure the ACD model, but the DVI-ADC Adapter brick is Model A1006. The ACD is Apple HD Cinema Display, 22" I believe. I realize it's not the exact same ACD as in this thread, but my problem seemed the same, and I don't see any other threads about this problem for other models.


    Oddly enough, though, last night I unplugged the power source, plugged it in to another wall socket, and the Display came to life! So far it's working fine, but we'll see for how long....

  • robin2468 Level 1 Level 1 (0 points)

    RE 23" Cinema display (purchased Jan 2007)

    It Happened to me as well.   Some electrical work being carried out - house power off - back on, NO DISPLAY and short-long-short led blink. 

    I hunted round this forum and found dozens of posts with exactly the same problem under exactly the same circumstances.. Surely there is a design fault somewhere. If you move the display from one room to another or just pull the mains plug out, the equipment should work again when plugged back in.

          Apparently, the inverter board in the display goes funny after a power outage.

    Took it to a Genius bar and found it would work with a 150W brick but not the 90W.

       Great, can I buy/order  the 150W brick? Answer absolutely not, it does not belong to the 23" display.  You will have to buy a replacement display, around $A900.00. No thanks.

    One solution, it seems, is to use the bigger 150W brick.

              Solution 2 was to cover the center pin (Earth - perhaps - see a previous post re this) on the plug or socket (from the display to the brick) with a small piece of plastic and isolate the (earth).

              I did that, and the jolly thing works. I now have my monitor back.

              I found it easier to fold a small, narrow strip of plastic, about 10mm long (off the tip of a small cable tie) over the center pin/s (over each side of the centre strip) of the socket.

         Hopefully it will last a bit longer (its only been a week so far).

  • hexdiy Level 1 Level 1 (60 points)

    Hi Robin 2648,

    thanks for your contribution.

    Nice to hear you/ people in this thread have found a solution, which I think after reading all of these posts is a permanent one. Would be great if at least some of you post your findings about this permanency point.

    ( Covering the center pins has been called "the jacobean solution" for a while now). Thanks for your feedback.

    Apparently, the inverter board in the display goes funny after a power outage.

    Nope, if the inverter board goes, you still get a phantom desktop image under strong lighting, whereas, in this thread, people get the infamous absolutely black screen combined with the " short-long-short" error message, meaning  "wrong powerbrick attached".

    It is my firm belief that this error message/behaviour originates somewhere in some kind of power sense circuit malfunction, thence the success of the "jacobean solution" or use of the 150W power brick.

    And hence my belief that blocking the middle contacts in the power plug/the sense lines is a permanent solution, provided your power brick has enough real reserve.

    If need be, use third party PSUs, I"lll get back to you on the connectors The older the TFT unit, the greater the power reserves should be, though not exceeding 24.5V,150W, I think.

  • RobWake Level 1 Level 1 (0 points)

    Cut a thin strip of paper and slid it over both sides of the center contact on the male connector (on cable from power block to monitor), and carefully slid it into the power block recepticle....  Fixed!




    I have renounced my current god, and now pray to Jakobeon!


    Thank you!

  • gsfunkarch Level 1 Level 1 (0 points)

    Add yet another to the list. C'mon Apple, stop sitting on your billions and try keeping your customers happy...

  • robin2468 Level 1 Level 1 (0 points)

    A follow up on my last post, Dec 2nd 2011.  I phoned Apple Tech Support (Australia  1300 321 456) and had a long discussion with a senior Tech. He could/would do nothing more than the Apple store - (Great, can I buy/order  the 150W brick? Answer absolutely not, it does not belong to the 23" display and Apple will not sell you a non specified part)- However he suggested that everyone with this problem (house power off or unplug - back on, NO DISPLAY and short-long-short led blink.) should phone Apple Tech Support in their own country and make sure that the tech gazettes it on their records, and make sure the discussion goes as far up as possible. Maybe if enough people complain long and loudly enough?????   I too, have used the Jakobeon fix, with success. Thank you all.

  • Drew Reece (Re:co) Level 2 Level 2 (310 points)

    @robin2468, it's odd that they keep telling you that the 150W power supply is not for the 23" display.

    The service source manual lists the 90W & the 150W for use with a 23" display. I guess the people you spoke to never get to read these manuals. Google for the PDF if you need to open up the display, it has troubleshooting etc.


    A freinds 2005 23" cinema display failed with the short-long-short error. Strangely a 150W supply didn't power it up. I found this post & tried removing the grey connection to the main board on the J1 connector. It's the same hack as the pin blocking posted on here. It works so far.



    @hexdiy, thanks for the pinout info you posted on It gave me the confidence to trust the hack is OK. I don't like the idea of blocking an earth/ ground pin on a metal display :^)


    I think I will try the LDO replacment that A1082 mentioned on the forum because the voltage regulator on the main board is outputting 4.2v instead of 3.3v. I'm just not sure about going for the 1.5amp or sticking with the same 0.8amp rating.


    Anyway, thanks for all the advice & sleuthing on this post & the otheres mentioned the display is alive again.


    I guess there is one good thing Apple has done in this whole mess - not deleting this thread.

  • hexdiy Level 1 Level 1 (60 points)

    Hi Drew,

    glad to hear my posts have been helpful to you.

    As to the Powerbricks: I don't need a manual to tell me the 150W issue is perfectly capable of powering the 20", 23" and 30" models, as the 90W issue can power both the 20" and the 23" models. The 65W issue only powers the 20" ACD. Simple electrics, I know you understand. If the voltage is right (in this case 24.5V), overdimensioning the Amperage is never a problem. The inverse is. A circuit will only draw the amperage it needs, issues only occur when the PSU is not up to par. So no need for the flawed sense line if you know what you're doing.

    As to the LDO replacement, I suggest you go for the overdimensioned version if at all possible. Same reasoning holds here! BTW: 4.2V on that output is way too high. You certainly have a point there!

    Good luck. And yes, thank you Apple for this thread! With or without issues.

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