G5 Quad

[Byrd]

Hi,

a quick outing to a friend, as stored in a cellar for years, a "faulty" Quad G5. Definately a keeper provided I can get it going, fingers crossed it will be the LCS failure that I can rebuild. Largely stripped with no RAM, HDs, but looks like hopefully a 7800GT or Quadro card inside. It was apparently used in a render farm, so come on Quadro ...

And of course, no C19 power cable. eBay quoting $60+ for one, but local Radioparts came through with one $8.95! Sometimes there are better deals in the real world

I'll fire it up over the weekend and see what is happening!

JB

 

[Cosmo]

Good find! Let's hope it's still repairable!

 

[Byrd]

The Quad fires up, no chime, reporting an intermittent "two flashing beeps" (RAM not detected) and/or red LED "checkstop" error before the fans spin up fully (so loud it nearly sounds like it is about to take off, Harrier-jet style). I've alternated the known working DDR2 RAM to various slots to no avail, CUDA reset etc.

Next step will be to remove the LCS (the original single pump Delphi unit, superficially it looks quite good however - no visible leaking), remove and reseat the processors. I believe I can strip the system down to one processor card to diagnose if a CPU board is faulty. Some troubleshooting should get to bottom to see if the CPU cards, motherboard or LCS is causing all the bother. Worst case scenario is if the motherboard is faulty, it is fairly cheap to replace.

It came with a 7800GT, which will do the job!

JB

 

[ClassicHasClass]

This is sounding like mo'bo', but good luck.

 

[uniserver]

yeah those quad liquid cooled ones , its like they all have issues, i think it was basically apple was pushing the thermal envelope so far trying to get that G5 as far as they could take it,, just put all kinds of insane stresses Thermally, Electrically, Mechanically- The poor power supply and the motherboard, hit that power button and the lights in the house dim, :-D i've seen some very nasty pictures of what looked like a little leek, witch when covers were taken off looked disastrous on the other side.

 

[Cory5412]

Just for fun, before you get too far, I would take it to an Apple store and see what they can do for you. As of a year or so ago, Apple was still replacing these system.

uniserver: the lights in a residence (especially an older house) will dim when all kinds of high-powered systems are turned on. I lived in a place where a SiliconGraphics desktop machine with a 757-watt power supply dimmed the lights and sometimes tripped breakers. I see no reason why a G5 with a similarly huge power supply wouldn't do the same thing.

Of the G5s, which were kind of a poorly executed product on Apple's part, the liquid cooled models (including the quad) are some of the worst, just due to these particular reliability and build problems. I'm made to believe it's better in the quads than some of the earlier liquid cooled units, but it's still pretty bad.

 

[ClassicHasClass]

The quad actually has very good reliability scores amongst all G5s, even better than some of the early air-cooled models:

http://www.macintouch.com/reliability/pmg5.html

G5s are still iffy by comparison, but the quad did have most of the kinks worked out, and the dual 2.3 A/C is quite solid too. Those are the only PM G5s I bother with.

 

[Byrd]

This morning I realised I had the RAM incorrectly placed (you need matched sticks in both banks, but from inner slots to outer), I'm now reliably getting a boot chime but after about five seconds the red "checkstop" LCD turns on and the machine switches off. Now it's time to pull the LCS and CPUs; from what I've read even if the LCS looks OK the coolant may have evaporated out slowly and/or around the CPU block that I currently can't see. Still, some progress.

JB

 

[mcdermd]

My brother scored a free dual 2.0 G5 back in 2004 because the RAM was not installed in matched banks. A common mistake.

 

[Byrd]

You may be right mcdermd, I seem to be having luck - I installed more modules of better quality DDR2 RAM I had lying around; in this case some 1GB DDR2-800 modules that came from a faulty Dell XPS tower. 4 x 1GB in total, in the right slot placement (inside to out configuration). I should also note that the additional power cable going to the 7800GT was disconnected, now back in.

Much to my delight, I'm now able to boot off the 10.5 installer DVD; both processors are detected, it passes all the basic system tests according to system profiler. I'm now downloading the Apple Hardware Test for it (2.6.3) to confirm that more components are working. I don't have any SATA hard disks to install OS X so will have to swipe one from somewhere (my wife's iMac G5 2.1Ghz recently got my 1TB drive that I wasn't using in my NAS, huge overkill but won't be opening that machine up again - I'll have to look elsewhere!).

Of note, the fans are very noisy and ramp up in speed after a few minutes, I can only assume that this due to them overcompensating for the LCS. I can't trust the LCS as it's obviously never been touched. The Delphi LCS even looks DIY with all the crappy cables and connectors, Apple really were pushing it I do have an interest in PC watercooling so will hopefully able to rebuild the unit neatly and give this beast a new life!

I never thought I'd be lucky enough to have a Quad in my collection. Obviously it needs some TLC and is mostly stripped down, but with time I should be able to make it a really nice Mac to use.

JB

 

[mac2geezer]

Before you get too carried away disassembling things, try recalibrating the CPU's from the ASD disk. It "may" just fix the fan speed problem.