Quad G5 not booting - no OF, no early boot, no OS

[dpfenninger]

I recently purchased a Quad G5 on Facebook Marketplace. Case is in near-new condition, all internal components look fairly clean outside of some dust. When I first booted it up, I managed to get to a desktop, and pull up a few apps before the system froze. Upon trying to restart the system, I got nothing but a black screen. Since then, I have tried a multitude of troubleshooting options, including but not limited to:

• Swapping the hard drive
• Swapping the RAM sticks
• Resetting the PRAM
• Replacing PRAM battery
• Attaching an external boot drive
• Inserting the Apple System Diagnostic DVD
• Swapping the graphics card
• Pressing the SMC button on the motherboard

Nothing has worked. Most of the time I get nothing but a black screen. The handful of times I've managed to get at least something to pop up - the early boot menu (OPTION key), an Apple logo, or Open Firmware - the system simply freezes and/or never proceeds anywhere. For example, in the early boot menu, I can't even move the mouse pointer, and nothing other than the internal drive will show up, even when I've inserted the ASD DVD or plugged in a Firewire boot drive. And the one time I was able to get into Open Firmware, I was unable to type anything as the system froze once again. I do get a boot chime on a cold boot, so I'm hoping that means something can be done.

I suspect either something on the motherboard is fried and preventing the system from continuing its boot process and/or the LCS is shot, as the fans are pretty loud consistently throughout the case but especially from within the LCS.

The seller said it was working just fine for him prior to the sale, but ended up refunding me the money and told me to just hold onto the system, but I would love to get this up and running as I've been wanting a Quad G5 for my collection for the longest time. If anyone can suggest any additional things that I haven't tried yet, or can point me in the direction of someone who might be able to take a look at it (I'm in the Chicago area), I would greatly appreciate it.

Help please!!

 

[ifrit05]

Might be a good idea to re-seat the CPUs and repaste them. Not sure if that will do anything. Also, if you can try to repaste the chip on the back of the logic board, but that will take a considerable amount of time and effort.

 

[DearthnVader]

Could be the video card is flakey, I know you said you "swapped" it, but did you swap it with a known good video card?

Quads and other PCI-E PowerMac G5's won't POST without a working FCODE ROM video card, if it's flaky that sort of explains the troubles you are having, and it's the easiest thing to replace.

 

[dpfenninger]

Could be the video card is flakey, I know you said you "swapped" it, but did you swap it with a known good video card?

Quads and other PCI-E PowerMac G5's won't POST without a working FCODE ROM video card, if it's flaky that sort of explains the troubles you are having, and it's the easiest thing to replace.

I swapped it out for the stock card in my DC-2.3 G5, which works perfectly in that, so I know it's not the graphics card.

It's been very puzzling all around trying to diagnose this. Normally, I can pinpoint the issue with most of my retro systems...this one has stumped me thus far. I've never had a system not be able to at least get into OF or the early boot menu, especially if it's chiming upon boot up.

 

[NikolaPPC]

Remember that corrosion and patina can form on pin contacts, so try to reseat the modules a few times so that they can achieve proper contact and connection!

 

[dpfenninger]

Slight update...I got the system to boot again to a desktop after being off for a few days, but just for a few seconds before the system randomly went to sleep and then wouldn't go back to a desktop after waking it up. When I was poking around inside the system before booting it back up, I heard something loose inside and, sure enough, a capacitor fell out:

I suspect it came off the graphics card, as there is a matching capacitor with the same numbers on it, and there's a spot on the card that looks like where the capacitor should be. It's not the stock card that came with the Late 2005 G5s, but some sort of "EVGA" card that has two DVI ports and an S-VIDEO, not a card I've ever seen.

So it would seem that that is where the issue might lie. HOWEVER, once again, if I put in the GeForce 6600 from my DC-2.3 G5, which works perfectly in there, the screen stays black and the system won't boot.

I've ordered new RAM to see if that helps. I may also try to order another GeForce 6600 card to see if that does it, but otherwise I think the next step is to dismantle the CPU/LCS module and reseat everything there. If someone can point me to a really good tutorial on that, I would appreciate it.

Thanks!

 

[dpfenninger]

Another update...pretty sure the issue lies in the CPU module...

Looks like LEDs 2 & 7...

Hopefully just reseating the CPUs will do the trick. Will try to tackle it this week once the new RAM I ordered arrives too.
🤞🏻🤞🏻

 

[dpfenninger]

Finally got the long-enough hex wrenches to remove the CPU/LCS unit. Took it out, sprayed a LOT of dust out of it and the fans, put it back in, and same thing... got an initial boot into OS X, but after rebooting, nothing but loud fans, a black screen, and the same two red LEDs on the motherboard. Still can't pull up the early boot or OF screens, too.

Next step is one that I was hoping I wouldn't have to do as it looks like it's additional surgery on the CPU unit: new thermal paste on the CPU dies. But I haven't been able to find a really good, clear tutorial for the Quad specifically. Can anyone point me the right direction for how to do this with a Quad G5?

Otherwise, any other ideas for what might be causing this issue? Have looked around online for a CPU/LCS replacement unit, but they're all heinously expensive so would rather try to resuscitate this before going that route.

 

[panzerkiller]

My dual 2.5 has similar symptoms:
Bought from fb marketplace; first boot ok; during OS X reinstall, screen freeze, pressing power button to power off, then never live again:
press power button, white light on for a few seconds and off; no chime; then the dvd, fans starts making some sounds like self test, but no post on screen; I think the system enters some “hang” status since the white light off, because since then, pressing power button will bring white light on but not keep it. The only way to quit is keep pressing power button until system down.

All attempts failed:
New pram battery;
Press pram reset button, with power cable attached or not;
Reseating vga, cpu, rams;