Is my 23" aluminum ACD dead?

Hi- Sorry to be posting this so late to your problem.

It sounds like you might have a problem similar to mine. My 24" HD Cinema Display stopped working. The 75 W brick checked out OK, and the Apple Dealer wanted to send the display back to Apple for diagnosis. I found a thread online that suggested trying the display with a 150 W brick.

It worked! 150 W adapters are about $150. Much cheaper than the $500+ Apple wants for return and diagnosis!

It seems that for some unknown reason, some 24" HD Cinema Displays stop working with the 75 W adapter and need more power. You can diagnose the display's problem by the pattern of the blinking light on the front of the display:

Here’s what the flashing power light means:

* If you see three short flashes, the display is receiving the wrong video format or is set to an unsupported resolution. Make sure your display is compatible with the computer you’ve connected it to, and restart the computer. If the problem continues, try resetting the parameter random-access memory (PRAM) by shutting down the computer, then turning on the computer and pressing and holding the Command-Option-P-R keys. Hold the keys down until the computer restarts and you hear the startup sound for the second time.


* If you see a “short, long, short” flash pattern, make sure you’re using the correct power adapter for the display.


* If you see a “short, short, long” flash pattern, the display is detecting a backlight error. Check your display’s power connection and restart your computer. If the problem continues, contact Apple or an Apple Authorized Service Provider.


Hope this helps you!

Dan & FlashDog -
.
I came searching for info & discussion for the exact reason & topic.

_My Set-up_:
*Cinema Display 23"* - M9178LL/A - A1082 - late 2005 release
I am using it with the original power supply.
Display connects to MacBook Pro Core2 Duo
.
Earlier, when I first started noting the problem,
if I just left the display plugged (a/c & computer) it would sometimes
just come back on after 15-20 minutes or so.
( +of course I still had the MBPro's display to use in the meantime+ )
But now, it just doesn't come on.
.
As noted by others, I found sometimes connecting to a different a/c source helped.
But not anymore.
.
I have found message threads on this exact topic on three other Forums.
No real consensus on the precise cause of the problem ... nor solution.

In general, buying a new 90W adapter was ineffective and a waste of money.
Some people have reported success using the 150W adapter from the 30" display.
But others have reported this did not work for them.
So I'm not certain how to proceed without needlessly wasting money or time.
.
.

You know the curious thing is, the display does seem to communicate its presence to the MacBook.
I infer this this because the MacBook's System Prefs adjusts its settings and Desktop pattern
when I "Restart" or "Wake" from Sleep depending on whether the display is connected or not.
Curious.
.
.

Has anyone gotten anywhere with this? I also have a 23" that mostly doesn't work, but does work intermittently. When I plug it in, sometimes, when I hit the power button, I get a quick light on the front - I do not get the morse code lights. It's just one short one and then, only some times.

This all started when I tried to move the monitor across my desk and plugged it into a different outlet/UPS. Since I did that, the monitor basically doesn't work.

I could buy the 150 watt power supply, but I would hate to spend $100 on one of those only to find out it doesn't work.

Maybe it's time to give up and just buy a new 23-24" Dell or Samsung monitor.

My ACD 20" just have the same problem. I am using my macbook Pro for 2.5 years with the ACD as the external display, they work fine until few months ago. The external monitor sometimes goes black and have a long indicator LED comes out (not in a sleep like blinking), but some random time later it wakes up again.

The problem goes worse in this month. I start up the mbp, then plug in the display, the screen goes blue (meaning that the mbp recognize the cinema display) but just seconds the external goes black completely and won't turn on again. After unplugged and plugged again, still no result. Then I go the System Prefrence->Display, the system tells it has a Cinema Display as the second monitor but it just not turn on.

The USB still works, and I could still control the sleep/shutdown function on the mbp through pressing the power button of the external display...

It comes very frustrating... after hours of search on the Internet still no luck for most people. Is there any possible way to diagnose the problem in a accurate way?

I think I'm coming to the conclusion that this display doesn't like a certain set of power outlets or surge protectors. It wasn't working. I was about to pack it up and is essence, throw it away.

Last ditch, I pull out my MacBook Pro, move the display out to the living room, plug it into the MBP and an outlet. Fires up just fine.

Take it back into the office, hook it up to the PowerMac, works fine, but goes black within an hour. Cannot bring it back to life.

Just now, pull it back out, hook up to Macbook Pro and it's fine. I'm going to leave it on overnight and see. This is making me crazy. Really thought hard about buying a Samsung during black friday.

I have exactly same problem. The LED gives a blink, and nothing else. Im not sure if the "middle pin" trick will help this issue as i have no tried.

Is there any way to send a direct claim to Apple on this issue? I called my local Apple support in my country and they dont really care about the problem even though i pointed them to the discussions on the forum.

I have hardly had my 23" ACD for 2years and used it quite minimally, so its ******* me off that i should burry myself in powersupply purchases due to crappy electronic design.