Did the Command, Option, O and F keys. At the prompt and entered:
reset-nvram
set-defaults
reset-all

Worked like a dream, the user was none too happy as he thought it was really screwed and he was going to get an new Mac.

Fans on ‘high’….. the G5 is full of temperature sensors that are monitored in software, which fan and how fast it turns happens due to sensor feedback…..i.e. if an area gets hot the fan(s) speeds up.

However, if the Op Sys doesn’t load correctly within a set period of time, the ‘fail-safe’ condition is to turn the fans on hard.

This is clearly demonstrated with the Apple Hardware Diagnostics CD / DVD which being a ‘bare-bones’ only system has the fans running like a wind tunnel as soon as you boot from the disc.

Things to do / check before wielding screwdrivers….. ( remove all peripheral kit except KBd & Mouse first)

1) Repair your disc permissions via Disc Utility

2) Reset Parameter RAM ( command-option P R ) on startup until U hear the chimes 3 times

3) Reset NVRAM in Open Firmware ( Command- Option O F ) on Startup. At the (white) command line screen, enter as per above post:-

reset-nvram and hit return

set-defaults and hit return

reset-all and hit return ( machine now boots)

4) Run Unix maintenance routines if you’re not in the habit of leaving the Mac turned on 24 hrs a day…..

Start the Terminal Utility (utilities folder)….

At the cursor type:-

sudo periodic daily hit return and WAIT for cursor

sudo periodic weekly as above

sudo periodic monthly as above

Quit Terminal.

5) CLEAN your machine! The examples we get here are often choked with dust which causes significant overheating / over-temperature readings.

If you have access to compressed air, take the machine outside ( you don’t want dust all over the house), and the best way is to blow the muck out (machine OFF of course) with a pressure of about 20 psi. ( Air cans are ‘ok-ish’ but pricey, we use a small compressor).

Pay attention to the Graphics card heatsink and HDD temp sensor area. Dirt build-up here can be significant and cause problems.

Pull out the main CPU fan(s) and get a good jet of air through the CPU heatsink fins. (put fan back!).

Blow a good jet around /thru’ the two Two fans at the rear of the machine. These get filthy.

If you can, try to get a good jet of air thru’ the main PSU which is under the bottom plate. A flexible pipe bent around the gap at the front of the plate helps. The PSUs suffer with dirt quite badly and can become completely choked with dust and fluff, overheat and fail.

You might be surprised at the level of muck that blows out.

6) WHERE applicable, reset the pmu /smu - using the small grey button on the main logic board ( usually around the lower edge of the board). Unplug mains cable. Wait 10 secs. Press button firmly and precisely ONCE ONLY. wait 10 secs. Plug mains cable back in and replace covers. Start Mac.

7) DO NOT try to run these machines with the covers off. The acrylic plate directs air into the CPUs which can ‘Fry’ very quickly if the plate isn’t in place.

Re-Seat video card (usually AGP). Be careful not to break the plastic locking tab at the end of the slot

9) Take the machine back to its ‘factory’ RAM configuration. Remember these need to be in matched pairs, (start at the centre two and work outwards- [8 slot machines]).
Is it ‘happy’ with the original RAM config ? - Suspect one of the upgrade DIMMS & CHECK again that they are being installed in matched pairs.

10) Re-Install the OS using the ‘Archive & Install’ option at third screen in order to preserve your personal settings / data.

11) Minor maintnance point, but if the machine is 4 or 5 years ‘in’ - replace the system board battery….( the correct way around!)

Hope this lot helps someone out there, but if you’ve done all of the above and its still ’sulking’ you’ll likely need to drop it into an equipped repair shop for detailed diagnostics.

Regards,

JH

http://forums.macosx[...]t-67489.html

… were several others also experience sudden death. Mine was/is a G5 2.3 2GB RAM. Was running perfect for two years and four months with the same RAM and videocards. All of the sudden itcrashed on me. I have tried everything metioned here and on the link above.

I have no problems in reaching the open firmware. But I can’t start-up in single-user-mode (cmd+s). Here it freezes after “DART enabled” … and the fans gradually spins faster. Except for one time–I could start up in single-user-mode, run the “/sbin/fsck -fy” and then the computer started perfectly. In ran a few system updates and ranfor a couple of hours. Then I tried restarting and I lost the patient again. Haven’t been able to awaken the dead … yet …

I was having a very similar problem with my Powermac G5 dual 2.7gHz … this is a problem that’s been plaguing me for months, actually, so much so I took the computer to Tekserve and had them fix it up. They set I had a bad RAM set, and gave it back to me, and it ran fine for about 2 weeks… but this morning I had the same exact problem you describe.

I ran the procedure you describe, and now I do get the blue log-in screen (whereas before it went black after the white apple screen), but now neither of the users are coming up…

It’s also worth noting that I never got the folder with the question mark.

Anyways, I will try again and perhaps everything will work out, but I was wondering if you had any futher troubleshooting suggestions?

Thank you,
James

Chris

Thanks for posting this info.

Perfect!

/sbin/fsck -fy

If it tells you ***** FILE SYSTEM WAS MODIFIED *****, type the above again, until it says:

** The volume (name_of_volume) appears to be OK *** (where name is probably Macintosh_HD)

When that is done, type reboot and you should be gold.

I have had your issue and this has generally solved the boot up freeze. my problem at the moment is that i am again have the same problem except i cant access terminal mode. it seems to freeze on the grey screen and go into fail safe mode (when fans go crazy).

does anyone have any ideas??

crinx

I’m using a G5 dual 2.0 2gig Ram.

any help or advice would be invaluable to me!

thanks

Andy

Much obliged!

I hear loud fan noises, its starts up, and i hear the chime noise. And i see a folder with a question mark.

I will soon try what is mentioned above.
Does anybody have any other tips?
thanks

chris

Thanks for the post, Alex.