Q: Random Freezes and Panics - What does Tech Tools not Test?

I am not sure about this, but this is a procedure I have just completed on a friend's G4 that exhibited the same symptoms and had also got a clean bill of health from TTP. My feeling is that TTP does not really test the integrity of hard drive media, i.e. whether there are sectors on the drive (on which data already resides) that are bad.

I recommend that you back up your drive and reformat it, selecting the option to write zeroes. This procedure will cordon off bad sectors on the drive. (No doubt you know this is a long process; you can run it over night.) Then restore the original data. There are two advantages; the drive surface is verified comprehensively, and the drive is de-fragmented when you "restore".

Good luck, and welcome to the discussions.

vislander,

In addition to Eustace's comments, may I ask a few questions?

-Did these freezes and panics begin after adding memory to the Lombard? Memory in the top slot of some Lombards can cause these symptoms.

-Open your System Profiler > Hardware > Hardware Overview; is the 512K or 1MB of L2 Cache reported as present? The Lombard is known for failing backside L2 cache.

V,

Looking at the tests in TechTool Pro, running the full suite does test the L2 cache but take a look at your L2 cache as I described anyway.

Bad RAM is one of the prime causes of kernel panics and freezes. Here is an excellent troubleshooting site for KPs:

http://www.thexlab.com/faqs/kernelpanics.html

If your hard-reset means resetting the PRAM, this would explain why your powerbook always defaults to the internal HD. Startup volume selection is stored in PRAM and the internal HD is the default.

Regarding your media bay HD: There have been similar reports from other Pismo owners having problems with their media bay devices under OSX. This is usually the complaint: They cold start successfully with the optical drive in the bay; if they hot-swap the optical drive for a VST Zip100 drive, for example, the 'book freezes or just does not see the VST drive. Restarting recognizes the VST drive but then they have the same problem hot-swapping again. The usual fix is a deep flush of all the caches in OSX using a third-party utility like YASU, available at VersionTracker. If you try such a procedure, uncheck everything but the caches...see if in fact this solves the problem.

However, your problem may be different. Try this: When up and running from the 4GB HD, swap your media bay devices and see if you have the above problem.

In addition, if you get a freeze when booted to the media bay HD (and the media bay HD is the selected volume in the Startup Disk panel), force a shutdown of the powerbook. I believe pressing the power button until it shuts down works on the Lombard. Now try a cold start and see if the media bay HD will boot the Lombard. There is a difference between a soft restart and cold start but I can't tell you what that is.

Vislander,

I would try to make sure the RAM is at fault if zeroing the HD does not help. There is the possibility it could be some other component. MacFixIt has a tutorial on running Memtest or Rember:
http://www.macfixit.com/article.php?story=20050524014158525

If possible, I would run Memtest in Single-User Mode to limit the amount of memory grabbed by OSX.

Vislander,

I am glad you found the problem.

Please be aware that the early iMac, Wallstreet, and Lombard take special 256MB modules due to their Grackle memory controller. The 128MB and smaller can be generic if they meet the Lombards specs.

Here is an example:
http://eshop.macsales.com/shop/memory/iBooks-PowerBooks/G3-Lombard/