My G5 is not starting up / No Video

Hello-

I have a PowerMac G5 1.8 DP 512MB 80GB HDD that is not starting up.
When the power button is pressed, it sounds normal, and there are no LED's on inside the unit.
There is no display on my Cinema Display, and that is known working, I was just using it with my MacBook Pro.

I've tried reseating the Graphics Card & PRAM, and that's about all.
It seems that the keyboard is not detected because it did not seem to reset after i reset the PRAM, and the little light for the Caps Lock key did not light up.

It also does not have the original HDD and does not currently have an optical drive installed. I don't know if this has an affect on it, and I don't currently have another optical drive to test with. I also do not know what is installed on the HDD because this is the first time I've tried to boot it up in a while.

I don't know what to do, and I would really like to get it working again. Is there anything else i can try reseating/resetting?

I saw the other thread that was simaler to this, however in the other one, the PowerMac G5 would work after a couple of restarts, just not on cold boots. Mine does not do this, it always has a black screen.
Thank you.


Awaiting your help!
Thank you!

Kaji79 said:

Do you have any macs that you could take a working pram battery out of, and put into your g5? I would try that.

Click to expand...

No, I don't. Would you suggest I order one?

Oh! After having it on for two minutes or so, the fans speed up to full power (I think at least) as well.

I've tested the battery on it, and it registers a 3.61 on my voltimeter. I've also reseated the graphics and ram.

Where should the RAM go exactly? I have 2 256MB Modules, and they are both installed in the top memory slots, leaving two emtpy ones at the bottom.

OrangeSVTguy said:

Is your the 4 memory slot or 8? Your memory should look like this below:

4)----
3)----
2)----
1)256mb

1)256mb
2)----
3)----
4)----

But it does sound like either a CPU(upper slot) died or your logic board. If the lower one died, it will still usually boot up but will only display 1 CPU in the System Profiler.

Click to expand...

I have 4 memory slots, and the configuration looks like this:

1) 256MB
2) 256MB

Space in between

3) Empty
4) Empty


Would it be possible to replace the upper CPU with the lower one?

I also took all the RAM out. My computer still does the same thing as it does when there was RAM in it... Could it be bad ram?

max¥¥ said:

you could swap the upper and lower cpu's but the fans would run at full speed unless you did a thermal calibration, but that would be a small price to pay

Click to expand...

Well, I could at least tell if it was the CPU's that way... I think it's the best route to go.
Does anyone know where I can find some good instuctions as to do this. I've already found some on the internet, but are there model-specific ones?

OrangeSVTguy said:

You have to install it the way that I had posted. Using your diagram, remove from "Slot 1" and install in "Slot 3". They must be installed in pairs if it's going to work.


The CPUs are already calibrated. You only have to run the TC when you install new CPUs or logic board. If the upper CPU did fail, it will run just fine as a single 1.8ghz but you have to swap the lower CPU to the upper one first.


I have the service manual if you want it. Or you can also find it online if you search for it.

Oh and if you have access to the marketplace on this site, I have an extra dual logic board(same as yours) that you can have.

Click to expand...

I'm sorry, i'm kind of new here, where would I find the marketplace?

Thank you!

666sheep said:

You need to have 250 posts and be forum member for at least 180 days to see Marketplace section. http://guides.macrumors.com/Help:Marketplace_Rules

Meanwhile, install memory correct way and if it won't help, try other pair of slots. Make sure that installed RAM is DDR400 (PC32000).

Click to expand...

I'll try the memory replacement.

I had an older account from 2007 that I forgot my login details. I could use that if I could only remember it.

I want to thank everyone so much for their help! I appriciate everyone's time and dedication to helping others. Again, thank you.

I'll replace the Ram, and try switching the processors.