Apple Cinema Display 23" - Blank Screen, "short-long-short" LED code

Just want to report on switching to a 150W power adapter. I was told by apple they wouldn't sell me one for my 23" display. But I found one and it works great. And has been working great for nearly two years. And this is where it gets interesting. I blew the ciruit today running an AC unit. Low and behold, my cinema display didn't start up, the dreaded morse code. I had a horrably flash back. Started looking for another 150W thinking I blew the current one. But then thought, if the original 90W was blown and a new 90W didn't fix it, which I tried back then, why would a new 150W fix it. So.... I decided to plug the original 90W in to see if it would fire up. Well, it didn't, but..... I then hooked the 150W back up and walla, the monitor is back. So, somewhere in there it reset it somehow.

And now that I'm back here learning about the nifty cover up trick, I am excited to try that with the original 90W to see if in fact, that works. Add that to you basket of Apples.

Count me in as another whose monitor came back to life after doing the Jakobeon patch and a big thanks for that. But like Bertolt, my FireWire 400 suddenly became defunct. Fortunately, I have a couple of FW ports on a PCI card so I am able to use my FW drives without any trouble, but I am very curious why the main FW ports went inoperable.

As for Apple's horrible response to a clear defect, someone ought to put together a class action suit for breach of implied warranty of merchantability. The long litany of postings on this thread gives Apple clear notice that they are in violation of that warranty.

I, too, have an Apple Cinema monitor that worked just fine - until I moved it to a different room and then saw the nasty blinking "short, long, short" light. I came to this blog and saw all the positive responses to the Jakobeon fix, so I tried it - first two tries with paper didn't work, but then I switched to two strips of electrical tape. Ah, the relief when the light came on solid, followed by the monitor coming on! Thank you, Jakobeon!!

I am also amazed at Apple's non-response to this defect - this blog was started over two years ago, and at this point there are 14 pages of messages, all pointing to the very same problem. Unbelievable!

My cinema display (23", bought in march 2008) stopped working yesterday and the power-led started blinking short-long-short. After some searching I came across this topic. Skeptically, I taped a tiny bit of plastic foil over the middle ground pin and my display is working again like it always did before!

Thanks so much for this fix.

Just wanted to say thanks to Jakobeon for sharing this fix with everyone. Just revived my dead 23" ACD by covering the ground as suggested. Seems to be working great. Would think that after all this time, and so many similar failures, Apple might step up and acknowledge that this is a problem and... I dunno, maybe offer a better solution than jamming bits of plastic into the power-supply.

Another Cinema HD Screen fixed with the method Jakobeon proposed! Thanks a lot! 😎

Just wanted to add in that the method for inserting plastic in the middle pin also worked for me. I will say though, that at first, my 90W power adapter was shot, so I had to get a replacement off eBay, and I noted the serial numbers. This one is working great, and the hack did the trick. I'll still keep my eye open for a 150W adapter on eBay, just to make sure. In the meantime, I'm at least back up and running.

Thank you SO MUCH for this information. It's stuff like this that makes the web an amazing thing.

Thanks Jakobeon,

The covering of the tiny middle pin did the trick - utterly amazed!! You just saved me $1000 (NZ$ that is)

Many many thanks 🙂

Thanks Jakobeon!!

You are truly brilliant!! fixed my 20" after a power outage.

Chris

Thanks goodness I found this discussion. My 23" quit working after a split second power outage last night and jakobean's paper trick worked perfectly. Due to poor eyesight and fumbling fingers took me several tries and it was easier to put into the receptacle on the brick rather than the plug. Also found it was easier if I used a wider piece of paper the first time it was plugged in, then trimmed the paper down according to the impressions in it. Still don't understand how the power outage causes this problem since we have these occasional power hiccups quite often here. Thanks to Jakobean for figuring this out and saving $ for so many.

Chock up one more ACD 23 with this same exact problem. Given that there are over 93K hits on this forum, I'm assuming this is a highly widespread problem. I would really like to understand the root cause of this problem if someone has taken apart these units and examined the exact fault. For example, electrolytic caps are notorious for failing in power supplies. It sounds like to me that the problem is in the inverter, and maybe there is some power threshold right on the edge or a sensor that has failed in these units. It would be great if anyone has actually isolated the fault to the root cause component failure.

As for my display, I'm on the third 90W power supply provided by Apple as a bandaid. They seem to know something but wont really address this problem head on other than just giving you a 90W to passify temporarily.

This causes tons of hours of transporting the ADC back and forth to the Apple store. Fortunately we have 3 of them in Seattle, but it is still a major PIA.

I'm somewhat inclined to get a 150W supply also, but less inclined to try the insulator fix that fools the inverter protection circuit if that is what it does. Without knowing the exact nature of the root cause of the fault, this is a potential receipe for a house fire. People need to understand how products get tested for this type of thing by going through extensive UL tests, circuit fault analysis, etc. When you bypass a system, then you don't know how it alters the original safety testing and you put yourself or families at risk.

It might be that this is a perfectly legitimate bypass, but without knowing more details and facts, I would at least be careful to never walk away from your monitor, leave it on at night or leave your house with it powered on.

Or maybe someone has an official Apple statement that says this is a safe and tested mode of operation????

OK, on to trying to solve my issue too. This is highly dissapointing.

Hi you all!

I've just ploughed trough this monster thread in its entirety, and, wow- awesome! I regret very much that our beloved Apple is once more letting customers- and great fans at least in my case, by the way- in the cold. As per usual these days, I'm sure- sigh-... An extended warranty should obviously have been instigated about this a long time ago, but once more Apple is playing the by now alas habitual game of hide-and-seek.

This being said, it is really heartwarming to see people helping each other along, and in the end managing to help themselves. In this thread, especially Jacobean on page 2. Nevertheless, kudos to all of you!

As for my 2cents, the following: there seem to be several misconceptions as well as ungrounded :-) fears in this thread I would like to point out.

- ACD malfunction is -as with ALL malfunctions- a complex matter, and difficult to solve remotely. Most of them here do point in the same direction, though: dead screen and/or short-long-short flashing leds probably indicate the same issue at hand here, solved by the genious W-paper/tape fix or by using the 30" 150W power supply on the defective 20" and 23" units.

- short-long-short error message as we all know by now means "wrong power supply attached".

- To those of you with a supposedly defective 90W adaptor: try the 150W one, if the ACD is up and running disconnect it and quickly reconnect your 90W original. This may work, something of the kind has been hinted at either here or somewhere in the course of my research- probably both. Seems to reset some sensing circuitry, although a long shot.

- To those of you for whom neither the paper fix nor trying the 150W adaptor will work, also to all of you having different morse code error messages ( e.g: long-short-long: "inverter board malfunction"): I believe you have a different issue, for example a faulty inverter board.

- Faulty inverter board is easily recognized: the LCD actually still carries an image. Though it is no longer backlit, the image will still be visible under a strong external light source. The same goes for users with only partially lit screens: monitors this size from before the LED backlighting era carry several so called "cold cathode" neon tubes. A partially malfunctioning inverter board will cause 1 or more of them to stay dim.

- The (in)famous middle pins that have to be covered by Jacobean's fix are in all probability not ground wires, but- as some of you have already hinted at (as early as the 1st or 2nd page): SOME KIND OF SENSE LINE, sensing what sort of external PSU is attached to the ACD. For those of you who have actually opened the case of your ACD: somebody here suggested cutting and insulating the grey cable coming from the outside connector, as a more permanent solution than the paper fix. I believe he has a point. Leave all red and black cables untouched, please.

- EVEN IF 1 or 2 of these middle pins are ground contacts (I am pretty sure one of them would be), mitschmitsch on this page is probably correct in pointing out to us that although it may be a ground to the power brick, it remains isolated from the mains ground. BUT EVEN IF the ACD is not grounded by using the "paper fix", also carriyng in mind that the power brick only runs a relatively harmless voltage of ±24.5V, please bear in mind that the inverter board swings this up to an estimated 80 to 120V DC. Not at all so harmless. BTW, just thinking out loud, all suggestions welcome. What's more, there has to be an additional ground to the video card anyhow, in order to get a desktop picture. This one in its turn will be grounded to the main computer/mainboard PSU mains ground. So no worries, as the Ozzies say.

- As to cable overheating/ turning brown issues: I believe the people experiencing this after applying the "paper fix" may have covered more than only the middle pins in the connector. Thereby effectively cutting power wire section in half and overstraining remaining connector pins and wiring. OR: their cable may already have been damaged, remember there is also a factory recall on some Magsafe adaptors for the same reason!

- Last but not at all least, I would like to share this with you: some Canadian nephew with knowledge in electronics ( A1082, how appropriate) may well have discovered the main hardware reason for our concern here: a poorly dimensioned low-drop 5V to 3.3 V regulator on the ACD mainboard: http://www.ehmac.ca/mac-ipod-help-troubleshooting/75311-cinema-display-troublesh ooting-parts-2.html

QUOTE:

"I successfuly fixed my ACD what was dark and made 1short/1long/1short blinks.

I'll make pictures and post them here, but in short:

- replaced failed "1117-3.3SJ" LDO regulator [5V to 3.3V] located in a middle of main PCB.

This time I used slightly modified LM1086 what should handle max 1500 mA instead of 800 mA by original."

(strange dialect, I suspect he's from the Montreal area...).

All said and seeing all this, yes, I surely expect Jacobeans's fix to be a permanent one! Call it an educated guess. Still shame on Apple BTW! And all feedback very welcome of course!

Well, as they say, that's all folks. Hope to have been of some help at least.

Hexdiy

My early 2008 23" HD display failed recently. It simply stayed dark when the computer woke up. No blinking lights either. I tried the power cable trick, with no luck. I didn't have a spare power brick or anyone that I could borrow one from, so I proceeded to investigate the voltage regulator on the main board. It was reading about 1.5V on the 3.3V output, indicating it was bad or overloaded. I temporarily piggybacked an LM1086 onto it with some microclip leads, and voila! The screen lit right up. The voltage at the combined output was now 3.3V. I permanantly installed the new regulator in parallel with the old one and the monitor has been running fine for several weeks now.

There has been speculation that the original voltage regulators are going bad, leading to so many monitor failures. This may be the case, but it is also possible that another component (or components) are failing, and in doing so they are now drawing more current than the original regulator was spec'd to handle.

Hi David, thanx for your reply.

It seems you have come to the same conclusion as our Canadian nephew, A1082 ( in my last link).

And you raise a very legitimate question:

it is also possible that another component (or components) are failing, and in doing so they are now drawing more current than the original regulator was spec'd to handle.

You certainly have a point here. Ageing and heat, as we all know, affects components, especially electrolithic capacitors. I deem it very possible that the original design specced the components so closely as not to take this into the equasion. Not to mention my fear they do this on purpose: building an expiration date into consumer products has been common practice in the "free world" since the 1920ies, according to a documentary I have recently watched!

On the other hand, or confirming this fear, thermal design may have been outright bad, as with so many more recent Apple products- I hate to add! ( see 1st gen Time capsules, all IntelMac laptops etc...)

So overspeccing this 3.3V regulator may well be a lifetime fix, if no other component goes. And if so, there we go to repair it yet again!

As of this week, I have my hands on the real thing: a broken A1081 20" ACD. All I can say right now is that none of the PSU's middle pins are actually connected to ground- at least on the monitor side (i don't have the power brick), so get this myth out of the way once & for all! The so-called "Jacobean Fix" only cuts the sense lines. Still, this seems to work in a majority of cases.

I'll be posting my results presently.

Sounds like there is a business to be made out there repairing these units if you can identify the root cause issue. Electrolytic caps are a common problem with displays and can frequenctly be the main cause of reduced mean time between failures (MTBF) issues like this. I finally decided this wasn't worth my time and needed to get my display fixed, so I'm paying the $400 charge. We'll see how long that lasts and perhaps once this group figures out how to fix these, we'll have a nice You Tube video tutorial done by then. I don't believe the 150W supply is a good solution nor the center pin workaround.

Thanks for the continued analysis. If anyone could dcoument this with pictures of the boards and the exact part numbers, I could help with the power analysis as I'm a EE and work with electronics quite a bit, designing and buying parts.

If Lyitc caps are found to be the root cause, replacing them with ultra high quality caps with low effective series resistance (low ESR) can really make the difference. It is sounding like (reading between the lines), that cap replacements and a new regulator might raise the design tolerance of this design.

I wonder how many defunction displays are out there? I just checked on Ebay and cursory inspection looks like there are at least 2 of them.

Can people on this forum provide a reponse to if they have a monitor that still exhibits this problem? (i.e. dark display with 90W supply and blinking light pattern).