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2.7 G5 goes to sleep randomly at under high stress
Posted by: reekdaddy on 2012-05-31 19:13:44
I've been noticing my recently acquired 2.7ghz G5 has a tendency to put itself into sleep mode once in a while, particularly when the CPU is under high usage.

I've been monitoring it with Temperature Monitor but I can't seem to find any pattern to when it happens. It just goes off and comes back on as soon as I hit the mouse or keyboard (it did it while writing out this post)

Doesn't seem dusty or dirty inside... any ideas though? Sign of an oncoming death. Maybe it needs to be better ventilated (under a desk is not a good place for it)?

I'm downloading ASD for the G5, so I'm going to burn that onto a CD, take the door off the side, and set up a giant ionizing tower fan next to it on full blast, and if it passes like that I'll probably try some more stress tests with and without the extra fan. Temps have gone from around 100-105c to 85-88c since I put the fan on it though...

Posted by: ClassicHasClass on 2012-05-31 19:27:08
It does sound like high temperature failure. Alternatively, the power supply could be trying to die. That's not an uncommon failure with that model.

Posted by: reekdaddy on 2012-05-31 19:29:48
That's what I suspected, temps seemed unusually high.

It's been running since I posted with the fan on it though, and now the CPUs are averaging 78-80c instead of 95-105c. Significant difference I guess.

ASD is still downloading, but are there any tell-tale signs of power supply failure (as opposed to other issues?)

Posted by: ClassicHasClass on 2012-05-31 19:37:08
Other than spontaneous shutdown or failure to boot, none that come to mind.

Are you sure you want an ionizing fan pointed at the motherboard, though? Depending on how much ozone that puts out, that can't be good for the polymers.

Posted by: techknight on 2012-05-31 19:43:55
wholy shit 105c? thats HOT. over the boiling point of water.

Hell, a pentium 4 if it reaches past 70c it starts to become unstable, at least in my experience.

Posted by: reekdaddy on 2012-05-31 19:45:38
man... good looking out on my momentary lapse of reason there, that's a really good point.

and yeah i was kinda like 8-o when i saw 105c... anyway i just turned off the ionizer and its just blowing air now. it hasn't gone above 80 since i did that so maybe i'll just let this G5 have its own tower fan~

it looks like i'm going to have to wait forever for ASD 2.6.3 to download though -_-

Posted by: techknight on 2012-05-31 19:51:09
its not the watercooled one is it? Might need to find a copy of the ASD for that machine and tune the fans.

Posted by: reekdaddy on 2012-05-31 19:55:55
Nope, aircooled 2.7. But I did realize that ASD 2.5.8 supposedly works on my machine and that was infinitely easier to find and acquire. I'll be back soon with test results.

edit: ASD 2.5.8 keeps freezing on me... argh

Posted by: reekdaddy on 2012-05-31 22:35:04
It died on me a couple times while running (a proper image of) ASD 2.5.8... i guess there's something wacky going on either with the cooling or power supply or both.

thanks for the advice though everyone - i'm going to try and see if i can bring this back to life... different model G5's didnt use different power supplies, did they? like if i have a good one in a different G5 that's older (all the ones i have are PCI-X)?

Posted by: ClassicHasClass on 2012-05-31 23:25:27
G5 power supplies come in 450, 600 and 1000 watt. Original single 1.6, 1.8, 2004 1.8 DP and 2005 2.0 DP are 450W; original DP 1.8, DP 2.0, 2004 DP 2.0/2.5 and 2.3/2.7 systems are 600W. All late 2005 G5s (2.0/2.3 DP and 2.5 quad) are 1kW.

By died, do you mean power down? Why not make sure the thermal grease is up to snuff on the CPUs before doing the heavy duty power supply disassembly? (I do mean *heavy*.)

Posted by: reekdaddy on 2012-06-01 11:03:02
Man, I just wish I had the tools and skills to replace it with a normal ATX power supply...

I'm definitely going to be checking that all out though because I seriously am holding that off for last resort

Posted by: reekdaddy on 2012-06-01 16:13:28
sorry for all these double posts. i keep losing the ability to edit -_-

anyway, i failed to respond to your other question - yeah by die i mean power down. just shuts off, not sleep mode. i don't think it's shut off while running OS X though, only ASD.

by the way - what is the story with ECC RAM on these particular models? as you're probably aware, ECC memory is tons cheaper on eBay

Posted by: ClassicHasClass on 2012-06-01 16:41:40
ECC was only an option for the 2005 models. Frankly, I never saw the point. My 8GB in this quad is non-ECC.

Posted by: reekdaddy on 2012-06-01 16:51:27
Damn, got all the way to the heatsink to realize my torx screwdrivers weren't long enough to undo that heatsink!

I'll have to put this G5 to the side for now unfortunately...

Posted by: beachycove on 2012-06-01 20:53:31
Nope, aircooled 2.7.
There's your problem. It's presumably been hacked to be air cooled. The dual 2.7 was liquid cooled.

Posted by: reekdaddy on 2012-06-01 21:01:26
sorry, that was my mistake! it is liquid cooled. i forgot that different versions of ASD didn't correspond to air or liquid cooled models.

it is liquid cooled, but i'm still stuck for the moment as far as replacing the thermal paste goes.

for now it seems like i just need to get longer torx screwdrivers... man i hope i get this working! how bad is the actual separation of that enormous heatsink and the cpus, though? i can't find any guides that show the disassembly of the heatsink/cpu unit itself. only the before and after parts.

Posted by: beachycove on 2012-06-02 08:17:44
It is really easy on air-cooled units and I think the liquid ones have the same basic configuration of six or eight screws holding the heatsink and CPUs together. It should all pull out as a unit, from which point disassembly should be easy enough.

You'll most likely need to service the cooling system. Some good resources (here), which though slow and in French has lots of detailed photos, and here.

Posted by: techknight on 2012-06-02 14:50:39
liquid cooled. Thats what I thought... That opens up a whole new territory for faults here.

Make sure all your seals are good and not leaking, then make sure your pump isnt air locked where it cannot pump from being slightly low on coolant. Prime the pump if need be, and make sure the pump is even operating!

Posted by: reekdaddy on 2012-06-02 14:53:18
Thanks a ton for those links! Now I have somewhere to start from...

Luckily i'm fluent in French so I can understand those instructions :lol:

If it turns out there's information in there not seen in English guides I'll be sure to translate any missing info for the rest of us.

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