Apple recommends affected Power Mac 5400/6400/6500 users revert to Mac OS 7 Last week, we had a report on the growing number of users encountering startup problems with Power Mac 6400. As it now develops, this issue appears to affect some, but not all, Power Mac 5400/6400/6500 models. Apple recommends that affected users downgrade back to Mac OS 7 until this problem is solved. Here is Apple's official statement, as noted on the Performa Discussion Board:
Q. I installed Mac OS 8 on my Performa 6400. It ran fine for a few days, but then the computer booted to a flashing ?. I was able to start up from the Mac OS 8 CD, but Disk First Aid detected that the hard drive was damaged and I had to initialize the hard drive. I initialized my hard drive and reinstalled Mac OS 8 but the problem came back after a few days. What should I do?
A. We have received several customer reports similar to yours. We have collected information from customers on this issue and we are currently investigating them to determine the cause and provide a resolution. So far the symptom seems to appear only on certain Performa 5400/6400 and Power Macintosh 6500 computers. It's important to note that not all Performa 5400/6400 and Power Macintosh 6500 computer's are having this problem.
If you have one of these systems and you plan on installing Mac OS 8, we recommend you backup any important files before installing Mac OS 8.
If you have installed Mac OS 8 and you are having this specific problem, you may want to temporarily revert to Mac OS 7.6.1 or Mac OS 7.5.5 (depending on what you were running before) until a solution is available.
If you need to install Mac OS 8, you may want to consider partitioning your hard drive with Drive Setup. Install Mac OS 8 on one partition and store your important files on another partition. Several users have noted that this method has allowed them run Mac OS 8, without jeopardizing any of their files (since the problem only trashes the startup partition). [However, note that there may be other problems associated with a partitioned drive in Mac OS 8, especially if you use HDT, as noted the other day.]
Another response from Apple noted that, since the problem seems linked to cold starts, leaving your computer always on can can be a temporary work-around. Again, note that this problem is separate from the similar cold start problem, previously reported, that appears to be due to certain 1.2Gb drives. Finally, there is some indication that this problem may also occur on Power Mac 5300s. (Thanks, Larry Kahan.)