Display flashes to solid black intermittently

I think you might be right. Despite the fact that it said my computer did not need the update, I am wondering if it did it anyway. Because now that I have reattached the 24" to the no thunderbolt Mac again, what do you know, no flashing...

Thanks -pm for the link!

I second that. -pm's link to the firmware update resolved the issue for me as well.

I am reposting his link for the convience of anyone new who comes along. Otherwise look for a post by '-pm' on the previous page of this thread.

http://support.apple.com/kb/TS4045?viewlocale=en_US

I've been having this issue repeatedly. Apple service was not able to locate the problem. I tried every single trick on the support pages. The problem persisted so I bought another monitor and upgraded the graphic card to the ATI 5870.

Seems that the problem is not the monitor or the graphic card but somewhere else on my mac pro. probably the power source or something.

After one of those blackouts, I have to remove the card and inserted again in order to have a little bit more time between blackouts.

I've also noticed that the card gets extremely hot.

¿any ideas?

Some MacPro models cannot move enough air to keep some graphic cards cool. I had to replace my 8800GT stock cooler with an aftermarket one to keep it cool. It generates some audible noise, but the heat temperatures plummeted down into the mid 40 deg C range.

A quick test would be to place a fan in front of the Mac Pro and see if the blackouts stop.

I would also get a UPS for the MacPro and see if power fluctuations are causing blackouts next.

David

Thanks for the response David.

I'll try the fan and the ups

This problem had been happening long before I had this card. so my guess has to be the power supply even though the apple hardware test didn't find any trouble on the machine.

this issue is very frustrating.

Thanks again.

@Pindaro, have you applied the firmware flash to the monitor yet? There has been some misinformation that it (the flash) only applied to Thunderbolt equipped Macs. Yes, you will need to connect the monitor to a Thunderbolt equipped Mac in order to apply the flash, but once applied, the monitor will stop flickering off if it is the same problem many of the folks have had here. At least that is how it worked on my Mac Pro. My 24" display was about to be used for snowboarding, until the fix was published. I flashed it with my Thunderbolt equipped MacBook Pro, and it has worked perfectly on my older Mac Pro since.

Thanks for the suggestion William.

Right now my macpro is being tested by another apple technician (first guy didn't find anything hardware related on the mac but issued a part exchange for the monitor logic board)

I'm running a macbook pro with the monitor as I'm writing and there seems to be no problem with the monitor.

I'll check on the firmware flash just in case. thanks.

I just got the Cinema Display 27 + Dell 24 + MacMini Server two weeks ago. Facing the intermittent black display issue too. I have just upgrarded to 10.7.3. I was on the phone with tech support. Problem happens way more often when I am watching an HD video but could happen any random time. I could reporoduce the problem while running a utility given by the support guy to take a trace of logs, network activities, etc... I should be hearing soon from them about the issue. I have a feeling it's the Cinema Display itself that is doing that.

Anybody else facing the problem with 10.7.3, the Cinema Display 27 and MacMini?

@camgas

I have a similar setup and have been back and forth with Apple Support for weeks. I've spent endless time troubleshooting on my own. Turns out it has to do with both 1) having a secondary display connected, and 2) how much RAM you have.

Try disconnecting your secondary display, and all your flickers should disappear.

Additionally, it seems to be linked to the amount of RAM. My findings:

4GB + 4GB = 8GB total: produces no flickers

8GB (only a single chip) = 8GB total: produces no flickers (regardless of which RAM slot it's in.)

8GB + 4GB = 12GB total: produces flickers but VERY seldom.

8GB + 8GB = 16GB total: produces lots of flickers.

The final decision from Apple was: The machine is rated for a maximum of 8GB RAM, so don't use more than 8GB RAM because it's unsupported and Apple can't be held responsible for "side effects" such as flickering.

Hopefully this info will help you.

@orchetect

Very very interesting! I have 8GB+8GB! This is very helpful, thanks. I will go try to remove one of my memory slots and report back here.

@camgas

Yeah, I guarantee the flickers will disappear if you back the total system RAM down to 8GB or less. It's bizarre, but trust me.

Also, after every flicker you should notice a "Restoring DP Link" entry in the system log (Console.app). That's an easy way to trace whether you've had flickers happening even when you're away from the computer. You can do a text search for it in Console.app.

Make sure you tell the Apple Support rep about this corrolation to RAM. We need them to ramp up support for >8GB. I don't think OWC (who I assume you got the RAM from) understands that >8GB is not "officially" supported but they still push it on customers.

This is it! I found all these logs in my system log. I got my RAM from Amazon (Patriot.) I will tell the Apple support guy all this information for sure! Thanks again, I really appreciate it. I just tested playing some HD videos and there is not flashes any more.

When upgrading to Lion, the install asked me to disconnect one of the two cinema displays attached to the Mac Pro at the time - before it would update the firmware - which I did.

Now, the display that was disconnected during this update blinks. The other (connected during update) is fine.

I downloaded the firmware update mentioned in this thread, but it said everything was up-to-date.

Does the second display blink because it didn't get the firmware update? And, if so, how do I give it the firmware update if my Mac believes it's already happened?

andrew_smith wrote:

how do I give it the firmware update if my Mac believes it's already happened?

Hmm. I didn't think a firmware updater came with Lion. that is interesting.

As long as the non-updated monitor is the only one plugged in, the firmware update should work (again).

- sorry not 100% sure if the firmware update came with it - or just after from "Software Update...".

I disonnected the fine monitor and tried the update again with only the blinking one connected - but it says everything is up-to-date.

It wasn't blinking when I did this and it's not blinking now; hopefully it's sorted itself out.