iMac G5 20"

[X.IV]

Hello, I am reviving a project started during lockdown when I attempted to repair my old G5. It had been suffering frequent kernel panic attacks, which I assumed was bad capacitors - many of them had ruptured. However, one day it totally failed to boot and the HDD had died.

The situation now is that I have replaced all the capacitors on the MLB, cleaned the dust from the fans and ducting, cleaned off and renewed the thermal paste on the processor heat sink, replaced the PRAM battery and fitted a replacement 500GB HDD which I got already formatted and with Tiger 10.4.11 installed. It is a Seagate HDD with no errors on S.M.A.R.T. test and only 500 hours use. The G5 booted up OK and loaded the standard Tiger apps, although not alll the ones that originally came wiith the computer when I first got it. However, something doesn't seem quite right. It takes a very long time to boot, and I haven't even loaded my data and apps yet. Also, putting it into sleep mode causes it to crash every time. The keyboard and mouse freeze, it doesn't go to sleep and the beachball spins forever until I shut down with the power button.

So any ideas please? Have I damaged the MLB? Are there some configuration settings I have missed?

Thanks,

 

[X.IV]

Just to quantify 'long time to boot'. From the moment of pressing the power button to the desktop and dock being fully loaded and the Mac ready for use, is 80 to 90 seconds. A 17" iMac G5 1.8gHz I have been using, also running OS 10.4.11 Tiger, fully boots in 45 seconds with all my apps and data on board. Why would a 2.0gHz with fresh OS install take almost twice as long to boot?

 

[Dronecatcher]

Have you tried the standard resets? ie access Open Firmware (cmd+alt+o+f) and type:

reset-nvram
reset-all

 

[X.IV]

Thanks. Just to clarify, I have a PPC Mac. I understand that non volatile RAM is an Intel thing? I did replace the parameter RAM battery, and have messed about with the hardware, so resetting the PRAM seems like a good idea. I will give it a go.

 

[B S Magnet]

Thanks. Just to clarify, I have a PPC Mac. I understand that non volatile RAM is an Intel thing? I did replace the parameter RAM battery, and have messed about with the hardware, so resetting the PRAM seems like a good idea. I will give it a go.

Nope. NVRAM exists on both. It gets used for saving start-up parameters (like verbose boot mode) for either of Open Firmware or EFI.

 

[TheShortTimer]

Hello, I am reviving a project started during lockdown when I attempted to repair my old G5. It had been suffering frequent kernel panic attacks, which I assumed was bad capacitors - many of them had ruptured. However, one day it totally failed to boot and the HDD had died.

The situation now is that I have replaced all the capacitors on the MLB...

Congrats on replacing the capacitors. I have an iMac G5 with this issue and I would've had a go at replacing them had it not been for the fact that its LCD is wrecked. I'm curious, what equipment did you use for this task and roughly how long did it take you?

 

[X.IV]

Replacing the capacitors was fiddly. I used a 25W soldering iron with fine point made from copper wire. The power is needed to quickly melt the lead free solder and avoid overheating adjacent components. Once all the capacitors had been released, I had to go round again with a desoldering pump to open up the holes. I fitted quality capacitors with a higher voltage rating than the originals as recommended on several websites. However, these were slightly taller than the originals and made it difficult to close the case back. I stuck an insulating film to the inside of the case back above the capacitors, but I would recommend getting capacitors with the same dimensions as the originals. All work was done with the MLB earthed, on an anti-static mat and wearing an earthed anti-static wrist band. I suppose the whole job took me a day in total, so it's not commercially viable. Pretty much everything needs to be dismantled to remove the MLB.

It's not particularly difficult if you are used to soldering, just time consuming. Good luck if you decide to try it.

 

[X.IV]

Nope. NVRAM exists on both. It gets used for saving start-up parameters (like verbose boot mode) for either of Open Firmware or EFI.

OK, I reset the PRAM and also 'reset-nvram' in the open firmware commands as suggested. Neither made any difference. The iMac still takes 80 seconds to fully boot and entering sleep mode still causes a crash. I also noticed in system profiler that there is no data under firewire bus. The firmware boot version is 5.2.5f1

 

[TheShortTimer]

Replacing the capacitors was fiddly. I used a 25W soldering iron with fine point made from copper wire. The power is needed to quickly melt the lead free solder and avoid overheating adjacent components. Once all the capacitors had been released, I had to go round again with a desoldering pump to open up the holes. I fitted quality capacitors with a higher voltage rating than the originals as recommended on several websites. However, these were slightly taller than the originals and made it difficult to close the case back. I stuck an insulating film to the inside of the case back above the capacitors, but I would recommend getting capacitors with the same dimensions as the originals. All work was done with the MLB earthed, on an anti-static mat and wearing an earthed anti-static wrist band. I suppose the whole job took me a day in total, so it's not commercially viable. Pretty much everything needs to be dismantled to remove the MLB.

It's not particularly difficult if you are used to soldering, just time consuming. Good luck if you decide to try it.

Thanks for the lowdown.

Over the past year I've become pretty adept at soldering and I would've undertaken the repair if the LCD wasn't trashed. If I come across another one in better condition that's either free or dirt cheap and requires attention, I will definitely have a go now I have a guide to follow. Thanks again.

 

[B S Magnet]

OK, I reset the PRAM and also 'reset-nvram' in the open firmware commands as suggested. Neither made any difference. The iMac still takes 80 seconds to fully boot and entering sleep mode still causes a crash. I also noticed in system profiler that there is no data under firewire bus. The firmware boot version is 5.2.5f1

Boot times on a HDD, even with a G5, are still going to be uncomfortably slow. This is where adding in an SSD retrofit is absolutely essential. Even on an old G3 iBook running 10.4.11, I watched boot times go from, roughly, 80 seconds, down to about 39 seconds, after moving it from a 7200rpm HDD to an mSATA-to-PATA solution.

The other issues you mention are also the kinds of things a verbose boot might reveal (or, alternately, putting your G5 into FireWire target disk mode and mounting the G5 hard drive on another Mac with a FireWire port, to review the crash logs). For a one-time verbose boot, you can still hold down Cmd-V when pressing the power button. This will give you a one-time view of what’s loading, what isn’t loading properly, and other hints of places where your system might be running into trouble.

Did you, by chance, install Tiger on this G5 directly, or did you clone it from a Tiger install on another Mac?

 

[X.IV]

Agree that a SSD should be faster. However, I am more concerned that the 2.0gHz is taking twice as long to boot as my 1.8gHz and both running Tiger 10.4.11 The original 250Gb HDD in the 2.0gHz had failed, so I lost the original Tiger OS. I bought a replacement 500Gb HDD already formatted and with 10.4.11 installed. So I cannot answer your last question. One thing I noticed is that the apps on the replacement HDD included MS Office for Mac 2004. Was that ever bundled with Tiger upgrades? I assume it is a trial version which will lock up after a certain number of uses.

I will try the verbose boot to see if it reveals anything.

 

[Amethyst1]

One thing I noticed is that the apps on the replacement HDD included MS Office for Mac 2004. Was that ever bundled with Tiger upgrades? I assume it is a trial version which will lock up after a certain number of uses.

Some grey (restore) discs that were bundled with PPC Macs include a trial of Office 2004. Retail versions of OS X don’t include any third-party applications.

 

[B S Magnet]

I bought a replacement 500Gb HDD already formatted and with 10.4.11 installed. So I cannot answer your last question.

Curiously, you just did answer my question.

That install of 10.4.11 was optimized for whichever system it previously resided. Unless you know, beyond certainty, that that HDD came out of a spec-for-spec identical 20-inch iMac G5, then it is likely certain optimizations and configurations meant for the previous Mac are running into trouble on your iMac. The G5s, as a series (iMac and Power Mac) are kind of oddballs from the rest of the PowerPC line, in that a lot of kludges were involved to make it work on Macs. Some of the system-level components account for this, but only if the OS X installer is aware that it is installing the system onto a G5 Mac.

What I would recommend — no, what I do recommend — is find a retail image of Tiger 10.4.7 DVD, burn it (or put it on a discrete drive partition using a cloning tool), and boot from that DVD/partition to fresh-install Tiger on your G5. Then, let the Software Updater bring everything up to 10.4.11, replete with Security Updates.

I have a feeling this will stop some of the crashing issues you’re having now.

 

[galgot]

I have the same machine. Maybe once a year, it behave strange, fans at full speed, or random crashes.
It's easily fixed by a SMU reset , pressing this button :



The fact your crashes when putting into sleep mode makes me think of a power management problem.

 

[X.IV]

I booted in verbose mode and got a screen full of code and printing, none of which meant anything to me, so no wiser really. It didnt even stay there long enough to read properly before the imac continued to boot normally to desktop.

 

[B S Magnet]

I booted in verbose mode and got a screen full of code and printing, none of which meant anything to me, so no wiser really. It didnt even stay there long enough to read properly before the imac continued to boot normally to desktop.

That’s what it’s supposed to do, and unfortunately, no, it doesn’t stay up on screen for long. It definitely helps to spot places where it shows loading errors (like kexts), which means having prior familiarity with OS X’s boot process. I suggested the idea with the understanding you were familiar with OS X on a level on par with, say, the skill of swapping out board capacitors (something I’ve never had the courage to do!).

 

[galgot]

Or, what you can try, it can't make any bad to the HD/system and you will at least know of something is wrong with it, is :
- Boot in Super User mode by powering up while pressing Cmd - s on keyboard.
- Once all the wall of booting text as ended, at the prompt, type "fsck -f" (without quotes).
- Let fsck do his things, may take time. if at the end you read "system is Ok" or something like that, then no probs with your HD. If you read "The system was modified", then run "fsck -f" once more.
- Once finished, reboot normally with "reboot".

 

[X.IV]

Curiously, you just did answer my question.

That install of 10.4.11 was optimized for whichever system it previously resided. Unless you know, beyond certainty, that that HDD came out of a spec-for-spec identical 20-inch iMac G5, then it is likely certain optimizations and configurations meant for the previous Mac are running into trouble on your iMac. The G5s, as a series (iMac and Power Mac) are kind of oddballs from the rest of the PowerPC line, in that a lot of kludges were involved to make it work on Macs. Some of the system-level components account for this, but only if the OS X installer is aware that it is installing the system onto a G5 Mac.

What I would recommend — no, what I do recommend — is find a retail image of Tiger 10.4.7 DVD, burn it (or put it on a discrete drive partition using a cloning tool), and boot from that DVD/partition to fresh-install Tiger on your G5. Then, let the Software Updater bring everything up to 10.4.11, replete with Security Updates.

I have a feeling this will stop some of the crashing issues you’re having now.

Hi, that's interesting and certainly explains some of the issues. I could try contacting the seller to find out if they have any info on the system. Other than that, I still have the original install discs that came with the iMac. I didnt use them as that would give me Tiger v10.4.0 If I use those discs, can I still get to 10.4.11? I didn't know software updater was still available for Tiger.

 

[Dronecatcher]

As @B S Magnet said, you've got Tiger on the HDD thinking it's running a different machine - wipe it clean and install a fresh copy (download from macintoshgarden.)

 

[Dronecatcher]

If I use those discs, can I still get to 10.4.11?

Yes, connect online and it does it's thing

 

[X.IV]

That’s what it’s supposed to do, and unfortunately, no, it doesn’t stay up on screen for long. It definitely helps to spot places where it shows loading errors (like kexts), which means having prior familiarity with OS X’s boot process. I suggested the idea with the understanding you were familiar with OS X on a level on par with, say, the skill of swapping out board capacitors (something I’ve never had the courage to do!).

Er - no. I'm a clockmaker. I can do any fiddly delicate repairs, but I don't understand computer code. I could try getting a screen shot and posting it on here to see if anyone can throw some light on it.

 

[Amethyst1]

That install of 10.4.11 was optimized for whichever system it previously resided. Unless you know, beyond certainty, that that HDD came out of a spec-for-spec identical 20-inch iMac G5, then it is likely certain optimizations and configurations meant for the previous Mac are running into trouble on your iMac.

It is my understanding that OS X installs are usually machine-agnostic though, as long as the version is new enough to properly take to the system. So even if the install came from another machine and was performed using grey machine-specific restore discs, once the 10.4.11 update has been applied it should work on any PPC Mac.

It’s always possible that there are exceptions to this rule of thumb (I’ve never owned a G5) or that the install contains nasty surprises, so I concur that a reinstall using a known-good retail disc is very much worth trying.

I booted in verbose mode and got a screen full of code and printing, none of which meant anything to me, so no wiser really. It didnt even stay there long enough to read properly before the imac continued to boot normally to desktop.

You could record a video of the process and watch it in slow motion.

 

[B S Magnet]

Er - no. I'm a clockmaker. I can do any fiddly delicate repairs, but I don't understand computer code. I could try getting a screen shot and posting it on here to see if anyone can throw some light on it.

Paging @bunnspecial !

Hi, that's interesting and certainly explains some of the issues. I could try contacting the seller to find out if they have any info on the system. Other than that, I still have the original install discs that came with the iMac. I didnt use them as that would give me Tiger v10.4.0 If I use those discs, can I still get to 10.4.11? I didn't know software updater was still available for Tiger.

It would be easier to just grab a copy of the retail DVD installer (download #32 on this list), clone-burn it to a DVD (or to a separate drive partition… be sure to select Apple Partition Map and not GUID Partition Table if partitioning a hard drive!), and boot from that DVD/partition to run the Tiger retail installer. It will install the final retail install of Tiger which is designed for PowerPC Macs.

 

[X.IV]

I have the same machine. Maybe once a year, it behave strange, fans at full speed, or random crashes.
It's easily fixed by a SMU reset , pressing this button :

View attachment 2186978

The fact your crashes when putting into sleep mode makes me think of a power management problem.

Well Galgot was spot on. Resetting the SMU solved the problem. My Mac now fully boots in 40 seconds and the Firewire, Airport and Bluetooth are now recognised. It also sleeps and wakes as it should without crashing. Useful information as it's such an easy fix. Not quite the same G5 model though. The picture shows a first generation iMac G5 and the SMU is reset by pressing the button shown. Mine is a second generation iMac G5 ALS - it has no reset button. The SMU is reset by removing the power plug and after 15 seconds replacing it while the power button is held pressed. Then press the power button again to boot normally. Don't even need to open the case!

I did contact the seller of the HDD and he suggested manually selecting the HDD icon in 'start up disc' preferences rather than allowing it to be the boot disc by default. I did that, but can't say I noticed any additional speed improvement.

So thanks to all of you for your contributions. It has been a steep learning curve for me and these old Macs do seem to act up in unexpected ways when things go wrong. Pleased to have it working again. I attach the verbose boot data in case it shows something of interest.