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View Full Version : Ambient light g5 2.0 Imac SHUT OFF




yourashero
Oct 28, 2009, 09:53 AM
So I've done all I can find on the internet on helping my broken computer. It used to have the noisy fan issue and then it would shut off. Now after being off for 12 hours, it may shut off in 2 minutes, maybe in 30. I have reset the SMU by unplugging for 10 seconds and then plugging in while simultaneously holding the power button, then turning it on. Ive also reset the PRAM, but it still seems to shut off. Is it a bad power supply? I dont ever hear the fans blowing hard anymore.

If anyone has basic things to do, I'm all ears. I know last step is probably just reinstall OSX.

I'm on 10.4 right now.



rtrt
Oct 28, 2009, 08:19 PM
So I've done all I can find on the internet on helping my broken computer. It used to have the noisy fan issue and then it would shut off. Now after being off for 12 hours, it may shut off in 2 minutes, maybe in 30. I have reset the SMU by unplugging for 10 seconds and then plugging in while simultaneously holding the power button, then turning it on. Ive also reset the PRAM, but it still seems to shut off. Is it a bad power supply? I dont ever hear the fans blowing hard anymore.

If anyone has basic things to do, I'm all ears. I know last step is probably just reinstall OSX.

I'm on 10.4 right now.

Ok theres a lot of info out there on this board and elsewhere. if i try to summarise what i remember in a few points;

Could be faulty capacitors on the logic board or in the psu
Could be overheating due to those capacitors or some other reason - dust etc
There are some led's on the logic board which allow some basic diagnostics - that might be a good place to start

Am sure that others can add to the list and maybe suggest some basic diagnostics. So will move to what my problem was - i have the same mac - G5 ALS 20"

One recent post you might find useful here;

http://forums.macrumors.com/showthread.php?p=8722590

For me specifically the psu overheating was the problem - hard shutdown at random times etc. I could replace the capacitors, there are people out there who sell kits. But tbh i looks like a lot of work for someone like me who lacks time and good soldering skills.

So what i've done is removed the psu outside the case and used one of these to extend the cable

http://www.dealextreme.com/details.dx/sku.18878

There are too many pins on this cable, but this was ok on mine as there was room to overlap the 'spare' 2 on the lhs of the socket on the logic board.

I've tie wrapped the psu tightly to the aluminum leg - which acts as a heatsink as well as a mount.

Note that this will certainly be considered dangerous by anyone who knows anything about electrical standards in whatever country youre based.

I wouldn't do it if there were any kids around or if your not confident in working with these kinds of things for example.

Do it at your own risk and don't take this post as any kind of recommendation to do the same as me.

Have i covered myself enough with the last line :D

yourashero
Oct 30, 2009, 10:06 AM
Thanks for the reply. I'm pretty possitive I wont be able to do anything about it myself. I may try to find a repair shop in the area and see what they can do about it because I will surely destroy the computer.

Thanks again

rtrt
Oct 30, 2009, 03:09 PM
i'd think hard about spending lots here - i know i did a while back.

if the local repair place can do something cheaply then go for it.

but as an example - I think a refurb psu was around $120 a while back. So with time for diagnostics and fit you'd have to be looking at $150 plus for a replacment psu - as a complete guess.

California
Oct 30, 2009, 03:53 PM
Bet its bad ram. Get two 1 gig matching sticks, my mom has same computer, I just dropped in a new 500gb hard drive and two 1 gig sticks of ram, it flies on Leopard, btw.