We are seeing this too (see the attached screen shots). It started about 3 months ago with one system and is now occurring to various degrees on seven systems total. All systems have the same spec (see below) and are part of a 100+ system rollout. All systems are using the same image and the other 93+ systems are stable.
|- Mac Pro w/
| - 2 x 2.8 GHz Quad-Core Intel Xeon
| - 4.0 GB 800 MHz DDR2FB-DIMM
| - ATI Radeon HD 2600 w/ 256MB VRAM
| - EFI Driver Version: 01.00.252
| - Mac OS X 10.5.5
Initially the problem was very sporadic but it seems to have gotten progressively worse with some pockets of relief here and there. Also there is no apparent consistency to what causes the problem to occur. The following troubleshooting has been performed and we still have no definite resolution.
|- Swapped video card w/ a card removed from a system not displaying this behavior.
|- Swapped monitor (all 20” aluminum Apple Cinema Displays) w/ a monitor removed from a system not displaying this behavior.
|- Reset logic board, NVRAM, and PRAM.
|- Replaced video card w/ a new card obtained from Apple under warranty (several times).
|- Confirmed ATI Radeon HD 2600 XT Firmware Update had been applied to cards and none of the cards required.
| - See this thread for further info on Firmware Update.
| -
http://web.mac.com/sailhome/SailhomeMacZ/MacPro.html
|- Installed smcFanContol and raised all fan RPM settings by 200 to provide additional cooling.
| - Above was done based on the assumption the problem may be a thermal issue as noted in this thread.
| -
http://discussions.apple.com/thread.jspa?threadID=1376038&tstart=50
|- Updated system from Mac OS X 10.5.5 to 10.5.6 via Combo Updater.
|- Modified the image used for the Desktop background.
| - Above was done as the pattern displayed seemed to be based on the background as the pattern would change when the background changed.
|- Deleted/reset various user account preferences thought to have something to do with video issues.
|- Rebuilt user’s AD account transferring all data to new account except for ~\Library items.
| - Above was done after noticing whenever we were logged in to the local Admin account the issue did not seem to occur.
|- Searched Internet via Google using various criteria, Apple Discussions Forums, as well as Mac-Wizards archives.
The only “fixes” we have found thus far are to perform any one of the following procedures. Each will remove the pattern after it occurs but none are a long-term fix as the issue eventually reappears.
|- Move mouse cursor into lower left corner of the screen for a moment. All systems have this set as the “Start Screen Saver” Hot Corner. Moving the mouse immediately after the screen goes black will cause the display to appear normal - without the plaid-like pattern.
| - Above always works.
|- Select the Displays icon in the menu bar and switch resolution to another setting and then back.
| - Above usually works but not always and can actually cause issue if it was not occurring.
|- Select a Finder or application window and move around screen as if erasing a blackboard.
The only other option we can think to perform, based on what we know at this point, is to reimage the systems. Obviously this is a last resort and we are hoping to avoid as there is no indication this will resolve and it involves a considerable amount of work.
If anyone has any suggestions and/or comments on how to resolve I would like to hear them. TIA.
- Geoff
Geoffrey B. Howard
Lead Analyst
Macintosh Client & Engineering Services
Information Technology
Random House, Inc.
