Help. My PowerMac G5 suddenly died. It will click twice but nothing else happens. I have reset the PMU reset button but still nothing. Any hope?
Thanks
Irish Rover
Lots of things to look at. Sounds like you are not even getting to the gray apple, so the problem is pretty fundamental. I take it you are not even hearing the fans do the initial run up?
First thing to look to is PRAM battery. If it is more than a couple of years or, or especially if it has never been replaced, it could be the culprit.
If that doesn't work, then something that might work is the so-called rest and relaxation business of disconnecting the AC power, removing the battery and letting the machine do a cold soak over night, then put the battery back in, hook up the power and give it a try.
One other thought: is the G5 on a UPS backup? If so, that may be the problem as well, as those things have been notorious for silent failure on load application (though truly the alarm should sound when that happens). I spent about a half hour on that exact situation with my former UPS when the thing was on its last legs.
Lots of things to look at. Sounds like you are not even getting to the gray apple, so the problem is pretty fundamental. I take it you are not even hearing the fans do the initial run up?
First thing to look to is PRAM battery. If it is more than a couple of years or, or especially if it has never been replaced, it could be the culprit.
If that doesn't work, then something that might work is the so-called rest and relaxation business of disconnecting the AC power, removing the battery and letting the machine do a cold soak over night, then put the battery back in, hook up the power and give it a try.
One other thought: is the G5 on a UPS backup? If so, that may be the problem as well, as those things have been notorious for silent failure on load application (though truly the alarm should sound when that happens). I spent about a half hour on that exact situation with my former UPS when the thing was on its last legs.
Thanks for the reply. I tried a new battery and nothing. I still get the 1 click and then after a slight pause another click. Absolutely nothing else does anything. No fans, lights, chimes, etc.
Well, it sounds like the power supply is responding to the front panel button, but then immediately taking itself back down. I am assuming that you are not getting the initial "fan rush" when powering up, which makes me suspicious that the power supply has keeled over. Does you model have the diagnostic LEDs next to the RAM slots? I am wondering what LED 7 is doing (it should some on for a bit of time, then go out).
I'm not getting any fan rush at all. I don't see any diagnostic LEDs anywhere and nothing is lighting up inside or outside. I still just have my two little clicks.
The clicking you are hearing is an overload relay in your power supply. It is detecting a problem and shutting itself off. Sorry to say you need a replacement power supply.
I've been having this exact same problem since last October. I press the power button, a red light comes on inside the G5 followed by a click then nothing. The solution thus far has been to leave the G5 unplugged for a period of time. Now, when this first started happening I would unplug it for 10-15 minutes & then it would start right up. Unfortunately as the weather warmed up the time required increased until now where I'm back to getting it to start every other day. But, once started it runs flawlessly, not even a hiccup. This would seem to indicate that it is not the PSU, nor the logic board or even the battery. Believe it or not, I replaced the "new" battery i had installed hoping to eliminate the problem, with an old dead battery which allowed me to start up the G5 everyday for a while.
So, try letting your G5 sit unplugged overnight and if that doesn't work try 48 hours. If that doesn't work you might want to try replacing the battery with a dead one, who knows, it helped my situation.
My theory on this is that I've got a bad SMU and removing the battery helps drain any bad data and there is probably a capacitor somewhere that is also requiring a full drain.
MadMacsOR wrote:
The clicking you are hearing is an overload relay in your power supply. It is detecting a problem and shutting itself off. Sorry to say you need a replacement power supply.
I would tend to agree; the lowest risk thing to try is a power supply swap. You may have something else in your system that is immediately overloading the power supply, but usually that would be an obvious (smoke) failure.
i replaced the power supply with apple, swapped the battery and pushe the reset button and still led 7 (chckstop) lights when i push the power button and the computer will not start. the white power button sometimes stays lit....so frustrated any help please
The first thing you should probably do is verify whether or not your PSU is connected correctly. You should begin by verifying whether or not you have "Trickle Power". To do this remove the side panel & air deflector and check if LED 4 is on. If it is you have trickle power.
Next, measure the amount of resistance across Terminal 1 & Terminal 2. Nominal resistance should be above 200 ohms. If below 10 ohms you PSU is probably dying.
You may also want to try reseating or replacing the graphics card.
After Apple replaced my PSU I had to basically reseat all the connections to the logic board as there were many which were flakey at best.
There are also tests you can do to measure voltage at the terminals & bus posts.
As I mentioned above I have replaced the battery with a dead one & leave the G5 unplugged overnight and for the most part, this works.
If all else fails check out DT&T located in Fremont CA. At the very least they'll give you a free diagnostic, minus S&H of course.
Hi everyone, computer stats are below but I ran into this same problem. I left town for a few days and unplugged my system from the wall (ie now power going to it whatsoever as if you are plugged in to a power outlet the machine still draws a little power). Upon returning and plugging in my machine - the second I plugged in the power cord I got the 2 clicks sound, and on my machine the front side power LED indicator (next to power button) came on and stayed on. The power button was completely unresponsive even if pressed in for 20 seconds or more. I first reset the SMU/PMU (same thing basically though called both acronyms depending on your model. Look up the diy manual on this site for this) and no change. Next I tracked down a new logic board (mother board) battery. In my model this is a "1/2 AA" size 3.6V lithium. Most of them still use the 'coin' type batteries, but in this model it's this different one. Though I have not yet tested my logic board battery with a voltmeter I suspected it had died once I read that it supplies info to the PMU (power management unit which controls the computers power settings like sleep, wake, etc). So if the battery was dead then either the PMU data was gone, tweaked, or just not accessible. I replaced the logic board battery, still nothing. BUT - after replacing the logic board battery I reset the PMU button and my machine was fine. The telltale sign was that once I reset the PMU with the new battery the power LED on the front of machine turned off, as it should have been while the computer was off. I am so thrilled that this issue is fixed without further time/money/headaches so wanted to share here. Best of luck.
G5 PPC Dual 1.8Mhz, 4G ram, everything else stock components...except 2nd hard drive, DVD-RW, etc. lol
