I've got a PowerMac G5 running 10.4.6, and Classic won't finish starting up. It used to work, but doesn't appear to now, either from the main System Folder, or one that's on a second drive as a backup from another computer. It gets to the Mac OS 9, Welcome to Mac OS screen (on grey), but never gets to the extensions parade. TruBlueEnvironment takes up close to 100% CPU time (it's a Dual processor machine). If I start up with Extensions Off, it just sits there, eating up cycles. If I start it up normally, it actually goes into a hang (according to Activity Monitor).
I've tried all the standard remedies I can think of: Update Software, restart the computer, Fix Permissions, rebuild the Desktop, trying it from different user and admin accounts, replace the System Folder (installing Classic from Install Disc 2 that came with the machine), and even replacing Classic Startup.app. Nothing works.
Any suggestions would be much appreciated.