PowerMac G5 2 GHz Dual Mess
 

I have "inherited" this PowerMac from a frustrated family member. Here is what I know at this point. 512 Megs of ram (2-256 sticks) installed in the lower 4 banks, none in the upper four. No SATA hard drives are currently installed. Attempting to boot from an external firewire HD with OS X 10.5.

Also connected are an Apple optical mouse, keyboard and cinema display.

Once the power button is pressed, it lights, the fans spin up, spin down then spin up much faster and then the chime. But nothing afterwards.

I shut down using the power button. Reboot and no chime. I shut down. Install RAM in the upper four banks (2 more 256 sticks) and reboot. Same fan and chime scenario with chime, but nothing afterwards.

To sum it up, when I get the boot chime and then nothing afterwards, I will not get the chime on the next boot, but if I remove and replace the RAM, I will get the chime.

Any ideas on what my next step should be?

If you have only one pair of RAM sticks, be sure they are installed properly.
You probably also will notice that the power light on the front panel is blinking, because the RAM is installed improperly (or your RAM sticks are bad, or incorrect type of RAM)
Your PowerMac has no chance of booting with RAM in the wrong slots:
One equal-sized pair should be installed in the center slots, and NOT one pair together in one bank.
Count up 1,2,3,4, then 5,6,7 and 8
The center slots are 4 and 5 (and not 2 and 3, for example, which are in the same bank.
Add extra equal-sized pairs from that middle pair out, putting one stick in each bank

Will do and will report my findings.

You'll probably want to look at this post from the main Hints site on booting a PowerPC Mac from an external USB drive.

Edit: Be sure to note the first comment for its correction of a type on the post.

Is there any need to try booting to USB, when the OP already has a Firewire drive to try?

Good point. Thanks for catching my mistake.

The firewire drive I'm using, as I mentioned, has OS X 10.5 installed on it. Two flat panel imacs have successfully booted from it. In fact, this troublesome PowerMac G5 is the machine I used to install the OS onto the firewire drive. But there has been some different RAM installed. I will check the RAM config after work and post what I find. Thanks for your contributions so far.

Is the version of the OS on the firewire drive for PPC? While 10.5 has both PPC and Intel code on it, I don't know if an Intel installation will boot a PPC computer or vice versa.

Brett

"flat panel imacs" is very ambiguous. Are they iMac G4s? iMac G5s? iMac Core2Duos? What processor do they use?

Trevor

Good question. And yes, it is a PPC version of the installer. As I said, creating a disk image of the installer and then installing onto the firewire drive allowed me to boot the PowerMac and install the OS. Of course, it restarted with the Welcome to Apple window and promptly shut down.

This is an PowerMac G5 with a 2 GHz processor and 512 RAM

There is no "PPC" version of the OS X 10.5 install, it's universal.
A 10.5 system, if installed through a PPC Mac, will boot either PPC or Intel Macs (assuming models that can boot with 10.5)
An intel Mac won't intall 10.5, unless the destination hard drive is formatted GUID, which, in turn, won't boot on a PPC.
You CAN install a 10.5 system - booted to a PPC, with a destination hard drive formatted APM - that will boot either a PPC or an intel Mac.

I have to say a lot (60%) of the Dual Processor G5's that i have supported over the years have failed due to sensor problems and/or power supply issues. I had 2 more fail a few weeks ago(5-6 years old 24/7 use) with the same symptoms. I would also change the Logic Board battery as well as it is 5 years old.

You may spend a few £200 sorting this out only for it not to work correctly or you may get a few years use out of it. Leopard is long in the tooth in the Apple world and you will soon find that many "NEW" programs will not run on PPC.

RAM should be matched in pairs across the two banks and really 2GB is minimum RAM configuration for any Mac.
http://support.apple.com/kb/HT2248

All the best.

No, you made that clear from the title. The processor of a PowerMac G5 is obviously a G5 PPC processor.

I asked what processor the flat panel iMacs use?

Trevor

Update
 

Installed a pair of Apple 256 meg chips, matched properly in both banks. Powered on and got the chime, keyboard and mouse both lit up along with video.

With no internal HD installed, I connected a firewire drive with a bootable copy of OS X 10.5 installed. Rebooted holding the option key, the firewire drive showed as an available boot disk, chose it and about 30 seconds into the process, it froze.

Restarted, no chime and racing fans. If I continuously restart (7 to 10 times average) eventually I will hear a small "pop" from the speaker and I get the chime.

Machine will boot from Apple Diagnostic CD then freeze. It will not recognize OS X Install DVDs for 10.2, 10.4 or 10.5.

I have reset everything. Zapped PRAM, booted into Open Firmware and reset NVRAM. Will not boot in Verbose mode or safe boot.

This still could be a G5 hardware failure IMHO.

It will not boot off a 10.2 disk and overall you have not tried a retail disk yet grey disks will not work. You should really try with a disk in as well or even clone the 10.5.8 external and put it in computer.

Tore down the machine. Replaced the motherboard with a known good one. Installed 1 gig of RAM properly matched. Booted from an external OS X 10.4 firewire drive. Got the chime and reached desktop. I did nothing, just let the machine run for around 9 hours, occasionally checking that the mouse pointer was still available. After 9 hours, I launched Safari, loaded CNN, then quit. Turned off display. An hour later, frozen. Reboot. Invalid memory access. Reboot. Kernel Panic. Reboot. Invalid memory access. Is this one of the processors freaking out? I did reset PMU, but have not tried anything else such as resetting NVRAM, PRAM, Open Firmware, etc.

fooked IMHO....but suggests bad memory.
Have you run memtest.

I have seen this happen with a ton of G5's.

I have not run memtest. Will do that tonight. But what would have caused it to freeze after 9 hours?

I have supported hundreds of these Dual G5's over the years and come across just about every issue know to man or beast ! We had inconsistent behaviour, processor, power, logic board, fan and sensor failures....you getting the idea...

I have only one G5 left (single processor one which were all fine) to support all have been replaced with better more reliable hardware this was not Apple's finest hour IMHO.

You woudl need ASD ( Apple Service Diagnostics ) to really see where the problems are.

I have several ASD's, specifically one that is entitled "For G5 Systems only." The Mac will only recognize and boot from the CD when I press and hold the power button until I hear the long tone (Open Firmware) but then freezes or will give a message saying that the CD cannot be used on this system. Also, the RAM is known good, but I know these machines are picky. This machine is so not representative of Apple products.

There's two final versions of the ASD for G5 systems. Neither will boot the wrong G5.
2.5.8 will work on the most models.
2.6.3 will only work on the newest models. (those with PCI-Express slots) I suspect you have that one (version 2.6.3). You need ASD version 2.5.8 instead.
If you have replaced the logic board, without having a good version of the ASD to use, then that can explain at least one of your problems. The ASD has the processor calibration utility. If you don't run that after replacing the logic board, the fans (all of them) will run at full speed continually, and there's no way to get those fans under control without running the processor calibration.

Resolved Powermac G5 won't boot - no chime
 

After searching the internet for days I did finally try what I thought was an unlikely cause to this problem -- I changed out the video card. This solved the problem.

My specific problem was that when I pressed the power button the light was lit (no red diagnostic lights on the logic board) but after a brief spinning sound there was no startup chime and there was silence until the fans started up full blast. I had been using the computer and it suddenly turned itself off and I was never able to restart it until I replaced the video card.

If you want to test to see if this might be your problem -- before you spend money on a video card -- take the video card out of your machine and press the startup button. If you get the normal powering up sounds with normal fan noise it is likely the video card.

I had read this solution in one or more posts to this issue, but I couldn't see how that would work so passed over trying it in favor of other possible causes. I am posting this so others will take note that this is good advice even if it seems unlikely.

Good luck!