CPU A=Top

CPU B=Bottom

...and it will not start at all on CPU B, will turn on from A. After doing this, I will not get a video signal and the USB does not initialize, also no startup chime. RAM reseating and replacing does not help, PMU Reset does not help, GPU reseat/replace does not help, Battery replacement/removal does not help, I have tried everything and I am at a loss.

Also, when replacing the Logic Board, I forgot to replace the plastic shields for the back heatsink and CPUs, I also dropped the GPU screw into the PSU so I am wondering if maybe a short occurred and that is causing this.

⟐ Commented dezembro 24, 2015 at 13:00 GMT-7

⟐ Answered dezembro 26, 2017 at 11:52 GMT-7

I recently bought an old G5 Powermac Dual 2.0Ghz along with a 23" Cinema Display. Model is an A1047, EMC 1969, PowerMac 7,2, made June 2003-June 2004; all based on the Serial lookup on everymac:

https://everymac.com/systems/apple/power...

Aftermarket ad-ons, which were already installed:

• There is an aftermarket ATI Radeon 9800Pro 256mb Graphics Card installed. The GPU fan does spin.

• There is 1.5GB of RAM (6x256MB).

• It did NOT come with a hard drive, but I do have 2 working hard drives which I installed to see if I could get it to boot. One with 10.5, and one with 10.0 (although, I realize that everymac says 10.2 is the lowest it came with).

I have done research and haven't been able to find anything based on my specific problem(s):

• First, and this is the weirdest based on not being able to find anything about it….when power it on the LED light turned on as the button is press; however, as soon as I remove my finger the LED turns off - yet the machine is still running. Anytime after removing my finger from the power button (meaning that the LED is off while the machine is on) if I press the button the light will turn on, and as soon as I remove my finger from the button the LED power light turns right back off (but not the machine).

• There is NO chime.

• The fans ARE running.

• If I leave it running for about 1-2 mins the funs begin to spin very fast…it sounds like an aircraft! lol

• There is NO display to the, Cinema display, which DOES work as tested through the ADC to DVI adapter to my other Mac.

• Various, and working, USB keyboards and mice do not work. Caps lock will not light up, and the mice have no optical lighting underneath. Also, the eject button on the keyboard doesn't do anything.

What I have tried, based on other articles:

• Power supply does click when plugged in, read in the Apple manual that good ones often do that.
• Swapping the positions of the CPUs.
• Running only 1 CPU on the #1 (top) CPU slot; tried with both CPUs.
• Reseating the RAM.
• Using different combinations of the RAM (however using the same amounts, same locations on both sides).
• Removing the graphics card to see if the boot up chime will happen (read that can be a way to test if it is bad, when you don’t have an extra GC laying around).
• I was able to use a paperclip to open the DVD drive, and it does closed by itself when you push the tray.
• Replaced the PRAM battery.
• Tried resetting the SMU by pressing the SMU reset button on the logic board.
• Ensured the CPUs were seated correctly.
• Capacitors look good

Note, that in all of the various combinations mentioned, the power LED light does not stay on unless the power button itself is being pressed.

What are some of your thoughts here? I feel that testing the logic board and individual CPUs with ones known to work would be the next best approach; however, before going out and buying anything I thought I would see what others thought!

Hopefully, this can help someone else too!

Thank you for any help you may provide! :)

⟐ Answered setembro 24, 2025 at 10:36 GMT-7

It will run for weeks without problem, and then all of a sudden, it will just power off as if the cord was suddenly pulled out from the wall.

Sometimes, it is necessary to disconnect the power supply in order to reboot, sometimes not.

The /var/log/system.log shows a repeated Fan failure! message (see below for excerpt)

The power supply is usually connected to a power board that protects against surges. I also tried plugging directly into a power point via a standard extension cord - but same problem. I don't use a USP.

I installed temp monitor - it show 'memory controller heat sink' at 65-70C - not sure if that is a problem? Sometimes I have noticed that the CPU A temperate exceeds the 'Upper Limit' of 75

The fans don't seem to be a problem but I am not sure - I checked all the fans by booting up with the cover off, and all seem to be working OK. I guess there are fans in the heat sink which you can't see to determine if working.

I notice that the problem was worse during summer than now at winter, so maybe it is something to do with a thermostat overheating?

I ran the Apple Hardware test (from the CD that come with the MAC) - I initially ran it with the full compliment of memory but found that the fans went into a high rev, and the test (even the Quick Test) wouldn't complete.

So I uninstalled all but the original memory and ran both the Quick Test and the Extended Hardware test - both did not show any issues.

I had two internal hard drives installed - when I removed one of these, the power downs decreased making me think the unit is overheating with the extra drive?.

The Power Mac is under a desk with reasonable circulation around it front and back although it could be better. It was operating fine in the same position for 3 years prior.

Apple reseller says it is the power supply, but I think it is probably something to do with the thermostat closing the machine down.

Have reset the PMU.

Hardware Overview:

Model Name: Power Mac G5

Model Identifier: PowerMac7,3

Processor Name: PowerPC G5 (2.2)

Processor Speed: 2 GHz

Number Of CPUs: 2

L2 Cache (per CPU): 512 KB

/var/log/system.log:

May 22 00:03:05 Fella kernel[0]: Fan failure!

May 22 00:03:35: --- last message repeated 29 times ---

May 22 00:03:35 Fella kernel[0]: Fan failure!

May 22 00:04:05: --- last message repeated 29 times ---

May 22 00:04:05 Fella kernel[0]: Fan failure!

May 22 00:04:35: --- last message repeated 29 times ---

May 22 00:04:35 Fella kernel[0]: Fan failure!

May 22 00:05:05: --- last message repeated 29 times ---

May 22 00:05:05 Fella kernel[0]: Fan failure!

May 22 00:05:29: --- last message repeated 25 times ---

⟐ Commented março 15, 2021 at 10:43 GMT-7

Shall I remove them be4 test by AHT?

The errorcode become under the process when AHT is starting, after the choise of langues,:

THE ERROR MESSAGE IS

invalid memory access at %SRR0 : 00000000 . 010e9ab8 %SRR1 : 10000000 . 00003030

One problem is that i dont have orginal CD, and the AHT is from a newer mac G5, late 2005 (with SCI express slots).

Ive tried that AHT on a older G5/1.8 from 2004 june and then AHT starts. And i also can run the test successfully.

The G5 2,5GHz (2004) is indicating Hi temperature on "memory heatsink" when testing with temperatur monitor - and fan runs up and down all the time.

Ive tried to take all memory away- execpt on par, and change memory on the slots to - thre error code result is the same.

When testing with Techtool pro 4.6.1 - No error.

PLEASE advise mee - what to do?

⟐ Answer accepted outubro 04, 2018 at 4:46 GMT-7

I have a dual 2.3GHz Power Mac G5 (Early 2005) which has been working fine up until a few days ago:

I was typing something in Microsoft Word (2008) and the mac froze. I tried to boot it up again but it hasn't worked properly since, when you try booting it up it does one of 4 things:

-> Boots normally (but freezes again after ~30 minutes-1 hour)

-> Plays the startup chime but nothing else (no video or hard drive activity)

-> Boots and plays the startup sound but freezes on the grey apple screen (just before the spinning thing appears)

-> Powers on but doesn't play the startup sound.

I tried troubleshooting the RAM but didn't have much luck. When the Mac is running it shows the proper Dual 2.3GHz PowerPC G5 CPU and 2.75GB of RAM (4x 512MB sticks, 2x 256MB sticks and 2x 128MB ones) on the 'About this Mac' screen. I've also tried resetting PMU etc. but there doesn't seem to be any correlation between what I do and what the Mac does, it just does whatever it wants.

Yesterday I booted it up again using 2GB (2x 1GB sticks) of RAM that I took from my PC (and know to be working) and it recognised the RAM and worked for about an hour before giving me a Kernel panic reading:

System Failure: cpu=1 code=0000000A (Lock timeout)

Latest crash info for cpu 1:

Exception state (sv=0x3de97280)

I have the whole kernel panic photographed but I don't know how much is important (I can type out the rest if needed).

I realise it's an old Mac but it still works great (or at least up until now) and performs fine for what I need it for so I'd be grateful for any help, thanks :)

⟐ Answered julho 11, 2022 at 17:31 GMT-7

⟐ Answered janeiro 14, 2021 at 15:00 GMT-7

I did a lot of searching and people say they used the DVI > HDMI to TV without a problem.

Any tips?

⟐ Commented outubro 07, 2020 at 13:45 GMT-7

⟐ Commented outubro 24, 2019 at 19:47 GMT-7

⟐ Commented outubro 14, 2019 at 15:03 GMT-7

⟐ Commented agosto 21, 2019 at 4:18 GMT-7

I have an internal SATA Pioneer BDR drive. I have a Power Mac G5 2.0GHz dual with one internal HD.

I would like to dedicate the G5 for BDR data burning.

How can I go about doing this? From what I have read Toast 8 will run on PPC and allow for bluray disc burning. What other bits of hard ware do I need?

Just another note (kind of moot but for posterity I suppose)

The manual also volunteers the following on page 44:

Overview of Making a Data Disc

This section describes the basic process of making any data disc with Toast.

To make a data disc:

1 At the left side of the Toast window, click on Data.

2 Choose the disc format. For example, choose Mac Only.

3 Choose any optional settings.

4 Add files and folders to the disc by dragging and dropping them into the Content Area from your hard disk or the Media Browser, or by clicking the Add button at the bottom of the Media Browser.

5 Optional: Rearrange, rename and remove items from the Content

Area. See Working With Data Content on page49.

6 Insert a blank, recordable CD, DVD, HD DVD, or Blu-ray disc.

7 Click the red Record button, choose a recorder from the list, and configure recording options, such as “Number of Copies.”

8 Click Record to continue.

Toast displays a progress bar and status information as it records your disc.

There is an interesting discussion that I am in the middle of reading, http://macintoshgarden.org/forum/blu-ray...

⟐ Commented março 23, 2019 at 6:38 GMT-7

⟐ Answer accepted janeiro 20, 2019 at 10:07 GMT-7

A week or so later, it stopped again. Unplugging things from PCI cards seemed to get it going again. But, continuing to experiment, it went with it plugged in once again on one of the tries. Intermittancy. Could it still be the power supply, or are the either good or bad?

⟐ Commented outubro 25, 2018 at 16:34 GMT-7

When it was working recently I reset the PRAM, ...that gave me back my chime...

I pushed that tiny button under the RAM and that helped start it once or twice. I replaced the PRAM battery (a different type on this machine...shaped like a nickel and made by Panasonic).

I get a yellow light inside, a white one showing it’s on and a red one lighting up inside for a second, but no booting.

⟐ Answered julho 04, 2018 at 17:01 GMT-7

⟐ Answer accepted julho 02, 2018 at 4:59 GMT-7

⟐ Answer edited dezembro 02, 2017 at 17:01 GMT-7

Here's what I've collected so far:

During ALL Startups:

Green(?), Yellow/Orange and Red light are always visible from when the computer is turned on to when it's turned off. No clue what this means, though.

The chime is there.

On Startup, an error messagee recieved when OF started:

Invalid Memory Access at %SRR0:00000000.ff84604c

%SSR1:10000000.0200b030

Apple PowerMac 11,2 5.2.7f1 BootROM

I got to OF by removing the USB while the screen was black. That was the only way I was able to get into OF.

Typing shut-down in OF:

Invalid Memory Access at %SRR0: 00000000.ff848988 %SRR1: 10000000.0200b030

Things tried:

Booting to a USB (Seem to get no display when a USB is plugged in, fans get faster after a while)

Resetting PRAM - Still leads to the flashing question mark folder.

Holding Command + V to boot to Verbose mode - leads to flashing question mark folder. Apparently seems to be a hardware failure?

Holding Command R to go to macOS Recovery - assuming there is no OS anyways?

Booting straight to OF from CMD-OPT-O-F leads to flashing question mark

Booting to the boot selector via holding Option on startup:

leads to the refresh arrow and and an arrow pointing right (exit?). I've put in a Win.7 CD but the mac did not seem to read it. I've put in a linux CD as well, to no avail. CD and USB seem to fail at this point. (I've put the USB in after i've gotten into Boot Selector as well- Nothing.)

Windows CD:

By somewhat forcing the CD Drive open, (have to manually open the door for it, then press the button thats inside the case), i've put the CD in and can hear the CD drive running, however after a point of time you can hear it stop, or at least slow down.

While booting to the Boot selector with a mouse plugged in, I pressed the left arrow and it seemed to crash to OF, though pressing any key does this.

While in Open Firmware from the above way^:

typing in ANYTHING (mac-boot, sync, test-all, any random letters, etc) leads to the error: "[Commandhere], unknown word, HERE= ffa3aa98

typing in help leads to "help help on is not available" ok

Booting to boot selector with no mouse:

Seems to hang the machine after the watch on the corner is gone. Return, any key command is unavailable at this point. Fans start to go faster, only way to shut down is by holding the power button.

Possibly Important Information:

1GB RAM, 320GB HDD Western Digital, Not sure of GPU But 90% sure it's the factory GPU.

No clue who the previous owner(s) were.

Any possible clues? Thanks in Advance!

⟐ Commented abril 28, 2017 at 22:03 GMT-7

Back-story aside, when this happened in the past I simply pressed and held ALT while simultaneously turning my Mac on and then simply selected the reboot disk drive symbol on the white backdrop and then proceeded to clear FCPro X caches where necessary in order to get my yellow bar of disk space back, so I can then start and/or finish existing projects.

Unfortunately, the MAC is not allowing me this option any-more for some reason. It simply restarts the same Dos Mode with 'unable to load' in that cream coloured text offset by that old school black DOS MODE backdrop.

Finally I am currently typing this post from my Windows partition thankfully but I still have No clue how to fix this, anybody experience this or am I the only one?

⟐ Answer accepted fevereiro 10, 2017 at 7:03 GMT-7