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rhogue islander · Aug 10, 2008, 12:29 AM

Hi,

I have a fall '03 PowerMac G5 dual 2.0

When I press the power button, the power light blinks three times, then repeats.

I get no startup chime and no grey startup screen. I've tried removing ram, unplugging the computer and pressing the little button down near the case divider all to no effect.

My google searches inform me that my logic board is most likely history and that apple's repair bill would probably total $1000.

Any troubleshooting suggestions are welcome.

thx

Kenneth · Aug 10, 2008, 03:33 AM

3 flashes mean no RAM banks passed the memory testing.

Did the fan and/or hard drive(s) spin up?

rhogue islander · Aug 10, 2008, 08:42 AM

Yes the fans spin up

I've tried removing all of the ram (6 x 512) and reinserting it to no effect.

reader50 · Aug 10, 2008, 11:37 AM

Change the order. Since the RAM is in pairs, if one stick fails, then the pair will fail startup test. If the logic board is ok, then you have at least 3 bad sticks.

How did this start, was your G5 OK up until some notable event?

rhogue islander · Aug 10, 2008, 02:46 PM

It worked fine up until yesterday morning, I went to wake it from sleep and the fans went on but there was nothing on either monitor. I powered down then restarted the computer and that's when I started getting the three blinks from the power light.

I've started pulling the ram in pairs and testing them in a pc using memtest. So far they all check out ok.

Andrew Stephens · Aug 11, 2008, 03:04 PM

Test the ram in pairs. When you test them don't forget that the memory boards are numbered BUT that Apple has mirrored them so you can easily end up putting RAM in non matching slots.

andyhhuang · Aug 12, 2008, 02:24 AM

Just want to add: the same happened to my 2003 Fall G5 Dual 2.0. I was watching a DVD and all of a sudden the system froze. I actually let it sit for a while, and started to force quit everything. None of the active application seemed to quit at all, so I pressed and held the power button until system shut down. Just like rhogue islander experienced, when I press the power button again to boot, there were no startup chime and no grey startup screen. The only thing that's different was that I don't see any blinks from the power light.

ChrisB · Aug 12, 2008, 10:00 PM

I agree. It's probably RAM. Change the order, and run Apple Hardware test.

rhogue islander · Aug 12, 2008, 11:33 PM

I believe its the memory controller on the logic board.

I tested all three pairs of ram in one of my pcs using memtest86 and they all checked out ok over several passes.

Its going in to the shop tomorrow, I'll keep you posted.

ttreen · Aug 18, 2008, 09:18 AM

Unfortunately passing a test in a PC doesn't always mean RAM is A-OK.
With each release of OSX, the Mac has become more & more picky regarding RAM.
This might not be the situation in your case, but I would definitely set a few hours aside to test them in permutations starting with only 2 DIMMS in...

robkoch · Aug 20, 2008, 07:40 PM

Started last night Dual G5 2.0Ghz 1 Gig Ram... was printing a job and stopped. No response. Now all I get is 3 blinks of the powerlight regardless of memory combinations. This machine has been running fine since I got it until I replaced a dead video card about 4 months ago. SMU reset does nothing. Fans start and then 3 blinks... Does anyone know how much the diagnostics are at an Apple Store?... I'd rather get an external SATA case and salvage the drive than sink more money into this beast.

reader50 · Aug 20, 2008, 10:19 PM

The problems described sure sound like the motherboard, since it's very unlikely that multiple RAM sticks would fail at the same time. However, there is one possibility.

Disconnect the hard drive(s), then try to boot from DVD. I've seen a system with a bum HD fail to boot, and it may have given me bogus error messages. Maybe it's a long shot, but this kind of test is fast & cheap. If it did turn out to be the HD, then that's fairly cheap to replace too.

zykron · Aug 22, 2008, 08:51 PM

I had a similar problem with an iMac (one of those power-supply-buggy ones), anyways try unplugging all peripherals from the computer except the keyboard and mouse. You could have USB and/or Firewire interface damage. Though I sort of doubt that would be the case, might as well fill in one more troubleshooting data point.

macwall · Aug 23, 2008, 04:22 AM

I have the same Power Mac and it for some reason it freezes randomly and then the CPU fans just go into turbo mode until I hard boot it off.

gradient · Aug 25, 2008, 11:04 AM

Originally Posted by macwall

I have the same Power Mac and it for some reason it freezes randomly and then the CPU fans just go into turbo mode until I hard boot it off.

I have the same G5 tower and have that exact same problem too. I can't let it go to sleep ever as after about 15-30 mins it will lock up and go into turbo fan mode. The Apple hardware test has always passed with flying colours, though.

andyhhuang · Aug 25, 2008, 05:53 PM

I took my G5 dual 2.0 to Apple Store last Thursday and found out that to replace the motherboard with labor would cost me $900 before sales tax (about $700 for the board and $200 for labor). Or I could just pay $100 to have it diagnosed without fixing it.

I bought a 20" iMac right on the spot. Anyone wants the parts from the G5?

macwall · Aug 26, 2008, 01:51 AM

Originally Posted by andyhhuang

I took my G5 dual 2.0 to Apple Store last Thursday and found out that to replace the motherboard with labor would cost me $900 before sales tax (about $700 for the board and $200 for labor). Or I could just pay $100 to have it diagnosed without fixing it.

I bought a 20" iMac right on the spot. Anyone wants the parts from the G5?

i would be interested to buying the whole thing. where are you located?

red rocket · Aug 26, 2008, 02:44 AM

I don’t think it’s the problem in this case, because of the power light flashing, but my G3 iMac didn’t start up yesterday (no light, nothing) due to a drained PRAM battery. Doesn’t hurt to check that before replacing the motherboard.

shotamodel · Aug 31, 2008, 07:15 PM

I also have one of these '03 Towers. Today, while watching a DVD the cpu just shut down on me. Now
when I try to restart it, the fan gets going, the monitors connect, then nothing. The computer just shuts down before I can get to the startup login. Is there something that can be done or am I also in the same predicament as Rhogue Islander? I have never had any problems prior to this.