So just last night the Sonnet 1GHz G4 ("U") arrived. I have a beige G3 desktop (to be transplanted into an ATX case as soon as the case arrives in the post). Prior to installation, the specs were as follows:
Rev C logic board
XLR8 G4 366MHz
Stock 230w PSU
PC 64MB ATI Radeon 7000 PCI (re-flashed)
Orange Micro USB/FireWire PCI card
IDE1: 12GB Maxtor HD (master), 60GB IBM DeskStar (slave)
IDE2: Stock 24x CD-ROM drive
I do not have a Royal VRM (I checked last year when I got the XLR8 G4).
So, first I uninstalled the Powerlogix cache enabler via Terminal. Next I ran the Sonnet installer that came with the drive. Then I restarted; got a kernel panic during bootup (most likely because of the extensions that the Sonnet software installed). I then put in the 1GHz G4, following Sonnet's instructions to the letter. The only discrepancy is that there was a sticker that says that the fans must be removed from the heatsink prior to installation on a beige G3 desktop, but in the actual instruction manual there was no mention of this, so I deferred to the instruction manual.
Once the chip was installed, I turned on the computer and everything was working beautifully. So I unplugged everything to take the computer back to my room to put it in its normal spot. I hooked everything up, started up the machine, and I heard a sound like a cable in the way of a fan, and I got a kernel panic on startup. I turned the machine off, and turned it back on. I got the sound again, so I tried opening the case and pulling the drive/PSU tray up a little bit, and the sound went away and the computer started up normally. So with the case panel off, I propped the case on its side, so that the drive/PSU tray would not press down on the CPU and make that noise again.
The computer was running for about 20-30 minutes, then locked hard. No kernel panic, just completely frozen. I turned the computer off, then tried turning it back on, and nothing. No startup chime, no video (in either the Radeon or the onboard); the only thing that happens when I hit the power button is the fans on the CPU and the fans in the PSU start spinning, and there's a brief flash of the LEDs on the keyboard and monitor (they turn on and off, only once per startup attempt as soon as the power button is pressed, very briefly). The hard drives make no noise at all. Earlier that day, I had used Disk Utility to repair permissions, and S.M.A.R.T. reported the drives as "Verified", so it is doubtful that it's hard drive failure. Also, the RAM is fine, and has been running fine for a year (with both the original G3 CPU, the XLR8 G4 CPU, and always running OS X, from 10.0 to 10.2 to 10.3; all clean installs.). I have also tried resetting PRAM, but to no avail.
The only thing I've found on Sonnet's support site that matches the behaviour I'm getting is this one:
But again, I don't have the Royal VRM, so I'm back to square one, as it were.
I have two ideas of what it could be: either the CPU overheated and died, or else the 230w PSU is not powerful enough to power everything with that chip installed.
Is this a good guess? Should I be worried about anything? Any ideas of what to do?