Debugging a PowerMac G5 DP - AHT

[Scott_2718]

Hi all,
I recently purchased a mid-2004 PowerMac G5 DP 2.0 GHz (PowerMac7,3). There is no chime, but it does boot from the hard drive, into 10.5.8. The optical drive constantly spins up & down. The optical drive tray does not open when the eject key is pressed. The top fans run at high speed, making it sound like a shop vacuum. The processor cover is held in place by only the top forward index pin and a plastic snap-in pin at the top rear. The air baffle is missing, which is baffling since there would be no resaon to leave it out.

I would like to get the optical drive working, the fans to run more quietly, and scrub the hard drive and re-install 10.5.8. I assume the temperature sensors don't work, so the system puts the fans on high as a fail-safe. I thought I would take it apart and clean it, but first run Apple Hardware Test (AHT) to see what it can tell me.

Booting while holding the 'D' or <option> + 'D' does not boot into AHT. I downloaded AHT PowerMac v2.5.2GMc1 (018-2216-A.dmg) from Apple, though I am not sure if this is the right version. I copied this to an external Firewire drive and ran the following in hopes of making it bootable:
sudo bless --folder /Volumes/FW_Disk/ --file /Volumes/FW_Disk/System\ Folder/System --label AHT

it did not.
The internet is replete with directions for making a drive bootable for EFI (Intel) Macs, but not for Open Firmware (PowerPC) Macs. Can anyone guide me on using AHT on this Mac? Any other tips on making this Mac serviceable would be appreciated.

Thanks,
Scott

 

[mustagcoupe]

Remove the optical drive and use a paperclip in the manual eject hole to open the tray, theres probably a disk stuck in it. If the air baffle is missing it will run some or all of the fans at full speed. Try sticking a piece of cardboard or paper in the back hole that the air baffle slots into, there is a sensor that detects if the baffle is missing and ramps up the fan speed. For AHT you will need to get a disk image for it off the macintoshgarden, the correct version should be 2.5.8. You will need to either burn it to a disk or restore the image to a partition on a firewire drive through disk utility. You can just hold down the option key to get to the boot picker and then pick the AHT disk or drive, the key to directly boot a cd is C, i do not know what holding down the D key does if anything.

 

[DearthnVader]

Remove the optical drive and use a paperclip in the manual eject hole to open the tray, theres probably a disk stuck in it. If the air baffle is missing it will run some or all of the fans at full speed. Try sticking a piece of cardboard or paper in the back hole that the air baffle slots into, there is a sensor that detects if the baffle is missing and ramps up the fan speed. For AHT you will need to get a disk image for it off the macintoshgarden, the correct version should be 2.5.8. You will need to either burn it to a disk or restore the image to a partition on a firewire drive through disk utility. You can just hold down the option key to get to the boot picker and then pick the AHT disk or drive, the key to directly boot a cd is C, i do not know what holding down the D key does if anything.

GitHub - upekkha/AppleHardwareTest: Apple Hardware Test Download Links

Apple Hardware Test Download Links. Contribute to upekkha/AppleHardwareTest development by creating an account on GitHub.

github.com

 

[Tratkazir_the_1st]

holding down the D key does if anything

AFAIK this is for intel-macs, start diagnostics (may be internet-based).