[dazsnow]

Yup, another "my powermac G5 won't start up" thread.

My mac: powermac G5, purchased October 2003. Dual 1.8GHz, 512mb RAM. Never had any problems before.

Situation: I plug it in, hit the button, the fans whirl but there is no chime.. after a while a click sound and then the front LED flashes 3 times and then just stays on but the computer won't start up at all.

From what I've read from similar stories on the forums, this usually indicates a RAM problem. However I am inclined to think it's a power problem. A few weeks ago I went on holiday and unplugged everything. When I came back and plugged everything back in I went to turn on the computer and this exact same situation occurred. I took the mac (all 20k of it!) to the nearest apple repair shop and in the shop there was no problem - it started up fine. I even got them to test my power cable. So... I took it back home.. and all I did was try and different extension cable and then it worked fine!

Now... I've just moved house. When I plugged it in and tried to turn it on I got the chime and a notification on the screen saying that I should restart the machine by holiding own the power button. This happened again the next time I tried to turn it on. The third and subsequent times have been exactly as before... fans... click... 3 flashes of the LED... and nothing.

I've tried all the plug sockets in the house and various extension cables but it doesn't look like that's going to work this time.

Any ideas? I will try replacing the battery this afternoon but if that doesn't work I have no idea... don't want to have to drag it back to the apple shop again only to find it works in their office fine.

Any help is greatly appreciated. Thanks.

[Big Mac]

3 flashes does mean incompatible RAM, and it could explain boot time kernel panics. Have you tried reseating the modules?

[imitchellg5]

Bad RAM. If you're getting the flashes, it's probably completely fried somehow. And if you only have 512 mb, sounds like it's time for an upgrade anyway.

[chris v]

Definitely RAM. When the power supply goes out on these, they're just stone dead, period. No lights, no fans, no nuthin'.

Go ahead and spring for 2 GB of new RAM -- it'll make your machine seem snappy, as well -- 512 is rock-bottom acceptable these days.

[dazsnow]

Well it turns out it was the little PRAM battery... or it least it was partly. After a very troublesome time of trying to get hold of one here in Beijing, I replaced the battery and the computer did actually start up. I got the lovely chime... the fans whirling.. the drive spinning... and grey screen with the apple... and THEN... "You computer needs to be restarted, please hold down the power button" etc. in several languages. I tried restarting about 10 times each time it was the same. Eventually it did start up normally and the computer appeared to be working perfectly... the only difference was that this time i tried plugging my ipod shuffle into the front to charge it up a bit but that surely can't have spurred the operating system to boot normally...

I didn't turn it off for a few days until I was setting up my wireless connection. The connection suddenly dropped after a few hours and then the airport couldn't detect any networks (there are usually about 5 in the vicinity). So... I restarted... then it was the same as before... just wouldn't get past the 'you need to restart' screen until after about 10 attempts i simply waiting on that screen and eventually it started up normally and works fine again only this time the airport card doesn't seem to be there at all... in the system monitor i mean.

I don't think i could have knocked it out of place when i was replacing the battery and now i'm afraid to restart the machine. Could it be that the airport card is faulty? Could that have been the problem all along do you think?

[reader50]

The next time you have to restart, hold down command-v to start in Verbose mode. It would be useful to see where the system hangs. The "you need to restart" message indicates a kernel panic, and the reasons can vary wildly.

[dazsnow]

will do. thanks.

[reader50]

Meant to add, if it takes several tries to come back up, then do the Verbose startup thing each time. It would be interesting if it hung on something different each time. Have a digital camera handy, or a notepad, to record what it says around the failure point.