Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.


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

Hello everyone.
This sounds like something of an epidemic... My Apple Cinema 23" HD Display (bought Dec. 2007) hasn't been turning on after a power outage hit our area last week.

The Computer and Display were OFF when the outage occurred. Everything was plugged into a surge suppressor. Everything ELSE plugged in to the suppressor is fine (including my Mac CPU)... but not the monitor.
It’s not dead-dead…. It’s a blank screen but there IS a morse-code flash on the LED (short-long-short). According to Apple Support’s LED Translation, it SHOULD be something to do with the power adaptor. The adaptor IS correct… a 90 watt… but just in case I bought ANOTHER 90w adaptor brick. I plugged the monitor to the new brick. THE RESULT WAS THE SAME.

I’ve tried power cycling, I’ve tried plugging it into different outlets, I’ve tried connecting to other computers. The same LED result remains.

And, yes, of course, I’ve got no Apple Support, and from what I read in similar posts, outside-the-warranty repairs could hit around $400. I REFUSE!

For now I have a Samsung monitor from Costco. It’s not bad, but it’s not the Apple monitor with its awesome color-fidelity.

I've read some other posts with the same problem (LED blink code and all) elsewhere but haven't got a solid answer.
I wonder… has anyone else incurring this same problem (with the same LED flashing deal) tried to use a 150-WATT adaptor brick? I would try this myself, but I’m currently financially unable (and personally unwilling) to throw more cash at this problem unless I know it’ll fix it.

Mac OS X (10.5.7)

Posted on


Page content loaded

Aug 3, 2009 6:06 AM in response to lebungleski In response to lebungleski

I just got this problem today. I dismantled one of the edit suites where I work and when I put it back together again one of the monitors started giving me the short-long-short flashing code. I KNOW the display was working before I took it apart, and I know I have put it together in the correct manner.

Now, what is weird is that the second monitor is fine, and when I swap power adaptors, the second monitor is STILL fine, even when using what is supposedly a bad adaptor. This leads me to believe that the adaptor is fine, but for some reason the screen doesn't want to accept it.

Can anyone help with this?

Aug 3, 2009 6:06 AM

Reply Helpful

Aug 3, 2009 11:35 AM in response to lebungleski In response to lebungleski

I recently started having the same problem with a 23-inch ACD after I moved the G5 it was hooked up to. I have two of these and both of the 90-watt power adapters work on one of them but neither one works on the problematic display. I also have a 30-inch ACD and the 150-watt power adapter will work on the problem display but after taking the 150 off and putting the 90-watt back on, same problem. This was all working fine previous to moving it. And no, it didn't get hurt in the move. It was handled very gently.

Aug 3, 2009 11:35 AM

Reply Helpful

Aug 9, 2009 10:17 AM in response to lebungleski In response to lebungleski

Hi lebungleski,

Same problem here - same monitor, same age. Fuse tripped in the house all sockets died. Monitor on at the time but also into power surge protection. Monitor would not restart, same short-long-short LED code. Took it to local Apple store today, spoke to "genius". Tested with a new 90W brick, no difference. Tested with 150W for 30" worked fine but they could not supply as they have to swap out like for like apparently. Over here in the UK it's £400 to replace the monitor.

Aug 9, 2009 10:17 AM

Reply Helpful

Aug 9, 2009 12:26 PM in response to lebungleski In response to lebungleski

Thanks, folks, for the replies.

I guess we're all hosed, but at least now I know (from your efforts) that a 150-watt adaptor WILL work. And since buying an adaptor will be cheaper than sending it in for repairs ($120 vs. $400), I'm more willing to take the leap and assume that a high-powered adaptor will bring my monitor back to working order.

Is there anything we can do collectively to inform Apple about this sort of thing? Would there be any chance that this would fall under "recall-worthy" issues, or is any effort like that rendered moot with it being "out of warranty"? I assume Murphy's Consumer Law and predict the latter, but I could be wrong.

Anyhow, thanks again, all.

Aug 9, 2009 12:26 PM

Reply Helpful

Aug 9, 2009 12:33 PM in response to lebungleski In response to lebungleski

I agree that purchasing the 150w adapter is cheaper than what Apple would require to repair or replace, and you can find these on eBay and elsewhere. However, I'm no electrician and I would worry that the 150w adapter would provide too much juice and fry the display in a short period of time.
Am I wrong?

Aug 9, 2009 12:33 PM

Reply Helpful

Aug 9, 2009 1:16 PM in response to tgapen In response to tgapen

Actually I think it's safe... in fact, on the one site (that I tried... and failed!... to link in my original post... http://support.apple.com/kb/HT2803?viewlocale=en_US ), it seems to imply (in the table at the bottom) that a 150w adaptor will power a 23" or 20" monitor. And the lack of any possible overload warning makes me think that it'll be okay.

... at least, I hope! Anyone have any extended experience with using a higher-than-standard-wattage adaptor on your monitor?!

Aug 9, 2009 1:16 PM

Reply Helpful

Aug 16, 2009 10:14 AM in response to jhames In response to jhames

As mentioned above, I've had this short-long-short issue for a few weeks now with a 23" ACD that's about 5 years old. After seeing this link http://support.apple.com/kb/HT2803?viewlocale=en_US I think it's safe to use a 150w adapter so I found one on eBay for $99. It works fine and if Apple says it's safe then I'm not worried about it. I wish there was an easier way to fix this but $99 is better than whatever Apple would charge to fix it or buying a new one.
I have three of these by the way and a 30" and they're all older displays now and I've not had any other trouble with them. I still think they're awesome.
If I have any other issues I'll report back.

Aug 16, 2009 10:14 AM

Reply Helpful

Aug 25, 2009 8:59 AM in response to lebungleski In response to lebungleski


I have also suffered from a power cut in my place and had some trouble getting my Mac Pro up and running. When I eventually managed to get it onto the network the 23" Cinema Display stayed off just showing 3 blinks (short - long - short). I googled the problem only to find this support page from apple:
This says that the blinking is showing a power issue. I then used the power supply on another 23" Cinema Display and it worked fine so I have taken a gamble and just bought the 150W power supply from the 30".

I will let you know if this works but I would be interested to learn how many people have been able to resolve this issue from upgrading from the 90W to the 150W power supply?

Thanks for the info.

Aug 25, 2009 8:59 AM

Reply Helpful

Aug 25, 2009 9:13 AM in response to thepikey In response to thepikey

Had the same problem (posted in a similar thread). Used my 23" for 2+ years on my iMac without problems. Upgraded several weeks ago to Mac Pro with 30" cinema plus my 23" as 2nd monitor. When I plugged the 23" into the new system, got the same short-long-short LED codes.
Read the support information from Apple where they indicate that the 150w PS is compatable with the 20, 23 and 30" cinema displays. Bought one of these and the monitor fired right up and has since been working fine.

So far so good...


Aug 25, 2009 9:13 AM

Reply Helpful

Sep 3, 2009 7:47 AM in response to lebungleski In response to lebungleski

Hi all!

As mentioned on the title of this topic *I HAD THE EXACT SAME PROBLEM* with my 23" Cinema Display...

Before the failure, the monitor *WAS IN PERFECT CONDITION* (trust me when I comment this, my whole life is in front of a monitor)

*THE PROBLEM SHOWED UP THE DAY I MOVED THE MONITOR TO AN OTHER OFFICE* (???). Please note that *I TOOK EXTRA CARE WHEN I MOVED THE MONITOR*, besides, when something costs around 1K you owe to.

*I TRIED AN 150W ADAPTER ON IT AND WORKED FINE!!!* Just like before.

But since *IT WAS UNDER GUARANTY* I sent it to the local distributor who eventually *REPLACED IT WITH A "NEW" ONE*, which after remarks from my side it turned out it wasn't "new" but re-manufactured by Apple (off course, he guarantied me the parts in it, where brand new and had 0 hours of usage).

In my question to the technical representative of Apple *"WHAT WAS WRONG WITH MY MONITOR"*, he answered me that *THE INVERTER WAS FAULT*.


That's my story... I hope it may help some of you... Personally I can't have an opinion on the matter, since I'm not a technician. The only thing on which I can comment is that *A 1K MONITOR SHOULD BE WAY MORE DURABLE AND TOLERANT WHEN YOU TRANSFER IT AROUND (if that cause the problem of course)*

Sep 3, 2009 7:47 AM

Reply Helpful (1)

Sep 3, 2009 10:02 PM in response to lebungleski In response to lebungleski

I have two Cinema HD displays that both went bad one with short-short-long and the other recently with short-long-short. The short-short-long would power up but half the screen would go dim. The top half of the CCFL would cut out. The code from Apple says bad backlight. The other with short-long-short would not power up with the 90w power supply. I decided to make one that works from two bad ones. I opened both-not very hard to do of you don't have a fear of it, and moving some aluminum-my guess would be on the short-long-short display the control board went bad. So from the monitor that had the bad backlight circuit (likely the inverter board) I took the control board out of it and swapped it out into the display with the good backlight but confused control board. Well after about half an hour of work, I fired it up and boom its working again! The control board may have just needed a 150W power supply who knows. The swap made one good working monitor and the other one broken with short-long-short control board and short-short-long inverter board.

Yay, I least I have one and its long out of warranty. What is sad in all of this? My 20" ACD late 2003 era purchased with the first gen MP G5 is still rocking it and much better in image quality. These LG displays are pure junk, too bad there's no way to get a refund on crap. I don't mind spending the money on good quality products but the Aluminum 23" Cinema HD is the worst.

Sep 3, 2009 10:02 PM

Reply Helpful
User profile for user: lebungleski

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