Start Up disk problem following kernel panic-mounts but not as a boot drive

Question

I have a problem that I can't solve.
Dual processor G4 with 3 hard drive, all of which are bootable drives with 10.4.7 installed:
A- my primary boot drive - internal SCSI drive (Adaptec PowerDomain 2930U PCI card);
B - internal hard drive that came with the G4; and
C - external Firewire hard drive
Recently, I booted into my B drive and it locked up after it went into sleep mode. On reboot, I experienced a number of kernel panic messages, prompting me to restart my computer.
PROBLEM: Since that time, I have not been able to get my A drive to once again be the Startup Disk.
Diagnostic steps that I have performed:
i. I have run and re-run Disk Warrior from a bootable CD and the A drive as well as the other 2 hard drives mount and are "repaired" by DiskWarrior.
ii. TechTools Pro shows no hardware problems and whatever glitches it has found were repaired.
iii. Disk Utilities consistently returns "Volume passed verification."
iv. Zapped the PRAM
The A drive does mount and is accessible whenever either the B drive or the C drive is the bootable drive.
System Preferences/Startup Disk lists the A drive as a candidate whenever either the B drive or the C drive is the bootable drive. However, when the A drive is selected in System Preferences, on reboot, it doesn't become the boot drive.
I have tried to restart and hold the "C" key down so that I might possibly be able to select the boot drive from A, B or C. But the C key method doesn't produce the intended result, only reverting back to the boot drive in power prior to the reboot. That occurs whether the boot drive is B or C.
At that stage, rightfully or wrongfully, since the problem persisted whether the B or C drives were the startup disk I concluded that the problem could be hardware related and not software related.
On one of the reboots following the kernel panics, a Crash Report was produced - the verbiage
which is code related and so far above my knowledge and experience that it is incomprehensible to me. I can post it separately if helpful but it won't fit in this email message due to restrictions on length of messages.
I haven't had a kernel panic following any of the last 50+ restarts that have accompanied my attempted diagnostics.
Finally, I ran the Apple Hardware Test, version 1.2.6, that came with my G4. First, I removed all peripherals except the monitor, keyboard and mouse (plugged into the keyboard), the Adaptec SCSI card, and a 3rd party FW/USB2 PCI card (OrangeLink+). I ran the Extended Test and an error code was generated during the logic board test: Error Code fire/5/2
That gave me some hope. I next removed the 3rd party FW/USB2 PCI card (OrangeLink+) and re-ran the Apple Hardware Test and no error were reported. Both the logic board and memory passed. I ran the extended test twice, each time no error.
Ah, did that solve my problem? I rebooted and I still cannot get my A drive to be the Startup Disk.
Next, I ran the Rember software (a GUI app for Memtest) and the RAM checked out as fine.
At this stage I don't have a clue. The white towel is about to be waved.
If the problem is the Adaptec SCSI card, I don't know how to test it since it obviously has to be installed to enable drive A to mount.
Does anyone have any suggestions?

Answer 1

I am the original poster on this thread.
Turns out that the culprit behind all my boot problems was the battery on my 5 year old Quicksilver G4. Replaced the battery and all is back to normal.
FWIW, for any Quicksilver owners with SCSI cards, be aware that you can create boot problems for your SCSI drive by zapping your PRAM. As part of my diagnostics I did zap the PRAM but that turned out not to be a problem.
Adaptec's site does include a workaround should you have problems after zapping the PRAM. This specifically covers the PowerDomain 29160 SCSI card/2930U card, which I have.