[puppetpigs]

Hi,

Our Mini (1.25GHz, 40G HD, 1GB DDR, OS10.4.11) has started to exhibit some scary symptoms. It started with not wanting to boot past the Apple logo and rotating lines. It also would not boot from the system DVD. Tried zapping PRAM, and all the other keystrokes I could find in one of our OSX 10.4 tomes. I restarted in "verbose mode" and got a continual "IO ATA Controller device blocking bus" mssg which, after a couple hours of letting it run, ended in a kernel panic. I could get the Hardware Test disk to run and came up with the following error code:

"2 STF/2/3 ATA-100ata-6-Master"

After letting it sit powered down overnight, I decided to try again. This time she booted up from the 10.4 DVD but Disk Utility kept failing to verify the internal HD because it said:

"Disk Utility stopped verifying “Mini” because the following error was encountered:
The underlying task reported failure on exit"

It also found an "Invalid key length"
Disk Utility did allow me to repair a load of permissions.

I assume that letting the machine cool overnight may have revived some failing components on the logic board, but I also wonder if the drive may just be on its last legs. The mini is now running successfully off the internal HD, albeit at slower speed with lots of spinning cursor. It makes an almost continuous low purring sound like the drive is softly writing.

Has anyone been through a similar experience? If it is a ATA controller, as seemed to be indicated by the initial hang, is that a replaceable part? Is there any Utility program that I can run that will help diagnose specific hardware issues (or can anyone decipher that Hardware Test error code above?). The internal drive could be a problem, but that doesn't explain the early refusal to boot from the system disks...

Any opinions?

Thanks!

[P]

You have a hardware problem. All the other issues you're seeing (in Disk Utility etc) are secondary due to the computer crashing. There are three possible cuprits:

* Your HD
* Your DVD
* Your motherboard

If either the HD or DVD is dying, that can mess up the function of the entire ATA chain. If the motherboard is dying, that can also manifest like this (the ATA controller is on the motherboard, and you can't replace it separately, so I'm going to refer to the part as the motherboard for now. If you're interested, that ATA controller is integrated into the so-called southbridge, which is the main chip that handles communication between the CPU and RAM and the other components of the computer).

Open your mini. That's tricky and requires a putty knife, but google for it and you can find lots of helpful pictures. From the error message, the HD is the most likely suspect, so let's try that first. Disconnect the HD - you can leave it in place in the box, but disconnect the cables. Try booting again and running the hardware test. Does it pass now? If not, try disconnecting the DVD and connecting the HD again. Try booting in verbose mode again. You might fail, if the directory structure is too badly messed up, but give it a shot.

If everything works without the HD, your HD needs replacing. That's easy and reasonably cheap - you need a 2.5" ATA drive. If it works fine without the DVD, you need a new DVD. That's harder, because it must be one that fits - a slotloader with the correct height. They exist, some googling can find them, but it may be cheaper to get an external instead.

If nothing helps, then it's your motherboard. Most likely one of the capacitors on it boiled over. If you can find a bad cap and you're comfortable soldering, you can attempt to replace it, but I wouldn't recommend it unless you really know what you're doing. That's the point where I'd start looking for a new mini.