Powermac G5 won't start up

Have you done a PRAM reset, CMD+Option+p+r...

http://support.apple.com/kb/HT1379

In fact, do 3 in a row, takes a bit of time.

How to reset the SMU/PMU on a Power Mac G5 (Late 2004) or Power Mac G5 (Late 2005) ...

http://support.apple.com/kb/HT1436

Earlier G3, G4, G5 models...

http://support.apple.com/kb/HT1939

http://www.macusersguide.com/2009/05/resetting-pram-nvram-pmu/

Hi, I have the same problem, I reset the PRAM, but the MAC G5 wont's start up.
I desconnected the electrical cable, press the start button, connect the cable and then wait 10 secs, after push the start button. No good .

Who have an idea ?
(sorry for my english)

Hi,
the red led coming on for half second, the power light coming on, ... a double "TIK" sound, and than the power light on in the G5 and in the monitor (cimena 20") stay "ON", but the MAC is not running.

thanks

Hi there,

I had the exact same problem, the lights, the clicks and everything.
It turned out to be one of my harddisks, i removed one and it just booted.

Later i re-connected it and it even had sparcles at the bottom.

Try remove your harddisks, it worked for me.

Sorry for my bad English.

I noticed my Power Mac G5 dual core 2.7GHz that I use primarily for pro tools had shut itself down overnight. Now it won't power up. No light, clicks or any other signs of life. Tried all the tricks, battery, reset button, etc and nothing worked. I would be simply giving up on the beast and upgrading to a new box, (rather than a costly repair,) however get this, the same machine did the exact same thing about a year ago. I gave up on it then too after trying to similarly fix, but about a month later I was moving my computer station and decided to plug it in, I pushed power and presto, it started right up. It has been running fine without any problem at all, for about a year, that is until this morning when I noticed it had again shut itself down and would not start up.

I am hoping the information about it starting after a long rest will give someone a idea as to what may be causing this to happen again. Any advise will be greatly appreciated.

Thanks!

That almost sounds like a bad capacitor that needs to bleed down, might disconnect everything from it, pull the PRAM battery & all power, let sit a few hours or overnight, hold power button in for 10 seconds, hook power & battery back up, connect everything & see if it starts up.

I found to leave it for 10-30 mins with everything unplugged, after you have waited plug everything in and it should work

Let me know if you have fiddled with anything, also is there sounds colours of lights?

Is the power light coming on, any fans, noise, anything?

Is there a ed LED lit on the logic board when plugged in?

Sounds like a problem with the 5 VDC l;ine if the LED just comes on for a bit... try disconnecting all USB items... does it stay on?

I've just disconneted all USB items but the problem continues.

Thanks

Here's some more info on G5 PSU voltage values:

http://www.insanelymac.com/forum/lofiversion/index.php/t105113.html

Thanks again. Yes that's what I did overnight last night and no dice..

We should continue this in the other thread that is yours. 🙂

Yes thanks. I was not sure I had posted to the correct area on the first one because of initial lack of response. My fault entirely.

I found to leave it for 10-30 minutes with every cable unplugged and plug every thing back in it worked for me!