G5 sounds like Jet Engine, then shut off and won't turn on

Just wondering if anyone has ever experienced.
Specs:
Dual 2 GHz PowerPC G5
1GB DDR SDRAM


The G5 started up like a jet engine. It ran like this for about 10 minutes and then shutoff. It will not turn back on. I have reseeded everything internal and still nothing. However, I do notice... when I connect the power cord back in the power light flashes briefly and then I can hear a small clicking noise.
Other than the brief flash of power when connected, the light does not come on when I push the button.

Any ideas? I could swap parts with another G5 I have, but I thought I would save myself some time and see what everyone here had to say.

Thanks in advance for any input.

~D

dphilly53 said:

I have reseeded everything internal and still nothing.

Click to expand...

Do you mean "reseated"?....."Reseeding" is something you do when you plant seeds for the second time in a garden...or spread grass seed on an existing lawn.

As far as the computer. Will it boot to the desktop? If not...that clicking sound sounds like a bad hard drive...or it could be a CD in your CD/DVD drive.

Hope this helps,

- Nick

Yeah..I remember that was thing with the G5...when it does not see any boot drives it goes into emergency mode powering fans slowly up to the highest output...sounding and pushing air out like a jet engine..sounds like a dead hard drive.

HA HA Nick... sorry for my grammar, but I have my best tech brain going right now, what is left to it, and not my spelling brain.

Going to swap hard drives and see what happens... that would be awesome.

dphilly53 said:

HA HA Nick... sorry for my grammar, but I have my best tech brain going right now, what is left to it, and not my spelling brain.

Going to swap hard drives and see what happens... that would be awesome.

Click to expand...

Good luck!

- Nick

Update:
G5A - sounded like a jet engine
G5B - perfect running machine

swapped hard drives.

G5A - good hard drive, still sounds like and engine
G5B - does not recognize hd, obviously it was a bad had in the G5A

now, WHY does G5A, with a good hard drive and boots up and I can login, STILL sounds like a jet engine?

Can anyone suggest some diagnostics to run????

THANKS! and STILL LEARNING!

Hey...things are getting a bit confusing.

- Are we now talking about two G5 computers (A & B)?
- And are you saying that the hard drive in G5A was bad...and when you installed the "good" hard drive from G5B into G5A...G5A still does not boot to the desktop...and still sounds like a jet engine?
- What are the specs on G5A & G5B...are they the same processor speed?
- Do you have the "gray" restore disks for G5A...or a retail "black" OS install disk? If you do, are you able to boot G5A from the DVD?

- Nick

Man I thought I was so clear! HA

ok - I have several G5's with the same specs... easy to swap hard drives because they all have the same config/processor/ram on them

*****- And are you saying that the hard drive in G5A was bad...and when you installed the "good" hard drive from G5B into G5A...G5A still does not boot to the desktop...and still sounds like a jet engine?*****

yes and no - G5A DOES boot to the desktop, but STILL sounds like a jet engine with the good drive in it. Here is my fear, it did this before and suddenly shut off and not the hard drive is toasted

- Do you have the "gray" restore disks for G5A...or a retail "black" OS install disk? If you do, are you able to boot G5A from the DVD?

YES! I DO! gray disks

~D

hold the phone... I was unaware of the red light, meaning the plastic cover is not on, meaning it runs in "cautionary" mode.

sorry to bother you Nick... it all makes perfect sense, I need a new hard drive

ok, I can wipe the sweat from my forehead now...

Yeah...you got to have that plastic cover in place before replacing the aluminum housing cover. If that's all it was...great...good deal that everything came down to a bad hard drive.

Good luck again,

- Nick

Fans racing will occur if the plastic air flow director is not in place. It is critical!

Guess what. Just put in new Hard Drive, attached all covers and JET ENGINE! UGH!

So I put in the gray disk and I am now running a Apple Hardware test.

Alright, serious help requested now.

My G5 has done it again. It runs, I counted, for about 16 minutes as a jet engine and then shuts off.
I can power it on again, but it is still a jet engine. It shut off in the middle of a Apple Hardware check.

ideas?

dphilly53 said:

Alright, serious help requested now.

Click to expand...

What have we been doing up to this point!

Did you install any ram or different video card before the problems started?

- Nick

well i thought the hard drive was the problem. But it has not fixed the jet engine. I guess I am going to swap piece by piece until I get no jet engine.

See this is the problem. I don't know WHEN this started. I have been redoing this lab and when I started this one G5 up, all heck has broken loose!!!

dphilly53 said:

See this is the problem. I don't know WHEN this started. I have been redoing this lab and when I started this one G5 up, all heck has broken loose!!!

Click to expand...

Since you have multiple identical machines at your disposal (which is a troubleshooters dream)...all you have to do is swap parts until you find the problem.

In fact...the quickest method would be to remove EVERYTHING...hard drives, video card, ram, etc. (maybe even the Airport card & bluetooth cards if it has them) from this "bad" computer...and replace all the parts with known working parts from one or more of your other computers. If this doesn't solve the problem...then you may be dealing with a bad logic board.

Hope this helps,

- Nick

dphilly53 said:

Alright, serious help requested now.

My G5 has done it again. It runs, I counted, for about 16 minutes as a jet engine and then shuts off.
I can power it on again, but it is still a jet engine. It shut off in the middle of a Apple Hardware check.

ideas?

Click to expand...

The machine in question is overheating and shutting down, hence the fans running like a "jet engine". It's likely a CPU issue. You can TRY and set the CPU settings to LOW in the energy saver prefs pane if you can get there. My Quad G5 has the same issue and this works for me, the machine is just a bit slower when using all 4 CPUs. As for starting, unplug the machine for 30 min and then boot it, it should work fine. Your run around with the hard drives was a waste of time.

As to the cause and posable fix, I only know that mine is caused by CPU A overheating, likely either a thermal paste issue, a clogged liquid cooling loop or a liquid cooling leak (least likely). It COULD also b a power supply issue but that seems unlikely also. My fix? Replace the machine with a new Intel Quad (perhaps even 6 core) MacPro by the end of the year. This G5 is 6+ years old and the G5 is a dead architecture. Time to move on.