It's an old thread but I have the problem and I have success in stopping it for long period of time. Read on.
The situation is ELECTRICAL in nature and has a bit of voodoo in the silliness of the solutions, but who cares, I've stopped the problem. Once I stopped it for over 1 year before having to do it again. Coming up with these solutions took 2 days of experimentation between 3 workstations all with silver MacPros 2009/2010, and the 2 Apple Cinema Displays, 1 is 30 inch DVI, the other is the smaller one, all hook ups identical, and switching them off back and forth for testing.
firstly - take the laptop conversations all off the table and off this thread, they cannot be related.
- unplug every single thing from every single port and power source and start fresh. If you count all plugins to brick etc, there are about 6.
- you MUST MUST change the way power is drawn from your wall or home outlet. This means a direct plugin to the wall - NO USE OF POWER STRIPS or surge protectors if you can help it. (you either want a true solution or you don't).
- Go buy a battery backup if you absolutely must release multiple outlets around the situation. You should plugin your MACPRO to the Battery backup, and the MONITOR also to backup or at least the surge protection choices (I mean ON THE BATTERY BACKUP not any strips! Invest in a real one brand APS recommended).
- NO splitters, no sharing of power source with peripheral devices, no multi outlet strips
- experiment with switching the ports to sources until you find a combo that works
- find colored tape and mark all the hookups to match so next time you recreate the solution that worked.
- Don't use the side power button at all. It's related somehow. Turning it off in system preferences has no effect. Mine is on, I just try never to bump into it.
- Yes, people who mention that the brightness icon goes crazy during these events is absolutely true.
- Yes, Apple has never cared about this even with Apple Care, so don't waste your time lugging everything to an appointment. They won't replace.
- Keep cables still, keep pets away from them, keep them NEVER MOVING if you can help it. My cat thinks the light on a surge protector is a fun button to push so it's taped in place (although I do NOT USE any of those strips for this monitor or computer pairing)
My opinion is that even the slightest variation or bump in the way electricity flows to the monitor, or through the mac causes the issue. After 1 full year of no issues, I brought my workstation gently to a trade show, had no problems, got back and forgot what was plugged in where, had no problems for 4 days, then I started using the side power switch because ***the sleep feature in the drop down menu takes nearly 2 minutes to actually "go to sleep" otherwise. The monitor went absolutely insane on one accidental use of the power button and I went through all the troubleshooting steps above multiple times until I found a situation that stabilized everything.
Also - I rarely can turn the workstation off because another issue with this monitor is after being off fore more than 24 hours, the first startup will display what appears to be a really insane screen of rainbow lines and static that move. It's scary, it looks like your monitor has shorted out, and the only way out is to do the dreaded, ill advised, pull the plug out of the wall and restart. Sometimes this method takes 3 restarts, and all peripherals must be pulled out of all ports then put back in.
The monitor is gorgeous, and gets attention wherever I go, but these problems have existed for 5 years. I say a prayer every time I restart that the dreaded "day of doom" doesn't come.
I was here today because everything almost didn't work and while I was typing, it mysteriously stopped.
Good luck to all. I hope something here helps. Like I said, I got a year out of it once.
