Computer won't turn on

[w0rm]

iMac g5 won't turn on it has isight on it (white model with can) no sound on start up or when anything pressed it's dead socket works it's a problem with computer.

Sorry for short stuff but it's an emergency and I'm on my iPod. Please respond asap or w0rm will be a name of the past

[Jedikiller]

I had the same problem with mine (iMac G5 ALS- no iSight)- it's common with the model, apparently.

Before reading this: you say it has an iSight. You mean it is physically in the case or it is external? If it's in the case/ the ports for connections are on the south rear, you're screwed. Take it to the Apple store and/or get a new computer- don't do what I say below. If it's an external iSight and the ports for the connections are on the west side of the rear, then keep reading.

You need to open it up (screws on the bottom, the back of the case just lifts up) and check the capacitors. They are the little round things on the southeast corner, looking at it from the top with the bottom south, I believe. If they are noticeably swelled up or bursting, then you have a problem. You need to replace the logic board of the computer.

Also, plug in the cord once the back is off. There are a set of lights inside numbered 1, 2, 3, 4. When plugging it in, see if the 1 light comes on. If it does, then this means the computer is getting power. Press the turn-on switch inside the computer (located here). Light 2 will come on momentarily if everything is fine, and the computer is recieving power adequately, but it can't be maintained. This is a PSU issue. Should Light 2 not come on at all, then there's a problem with the logic board.

Both of these repairs are very expensive- if the computer is under warranty still then take into the Apple store and see if they can fix it for free. If not, then you're SOL if you don't want to drop $200-1000 on it. Get something new.

[w0rm]

Nternal iSight, built in above the screen. So I should be screwed you say, but it just turned on. The fan was nuts tho, so I turned it off. Now it won't start. Coincedence? Or not. And I'm resetting the smu ATM. Ty for quick reply JK

[Jedikiller]

Mine would occasionally start up too, but it would generally go down soon after.

I believe that the SMU on those models resets itself due to the ALS on the bottom, but not sure.

There is probably still a solution to your problem, but since you can't get into the back of those models it's rather hard to replace things inside.

[w0rm]

Resetted smu manually with power cord and all and it turns on, but fan is crazy. That's the only problemo atm. Thoughts? And reckon it's safe to run nomally?

[Soap Mactavish]

[mod]Please refrain from posting flame-inducing comments. If you're not going to actually help don't post at all.
-Red[/mod]

[Jedikiller]

not sure where in canadia w0rmy lives but they don't have as many Apple stores up there as they do down here in the US

[SchTicK]

Have you tried "Safe Booting"? Tried using your install disk to start from? If you get it started repair permissions several times.

When the fans go wacky it means the computer can't tell how much to cool the electronics so it plays it safe and cranks the fans on high. Could be motherboard/logicboard.

If you have internet access read these threads on the Apple forums page:
http://discussions.apple.com/thread.jspa?messageID=10918896&#10918896
http://discussions.apple.com/thread.jspa?messageID=10915751&#10915751

The Genius Bar is your best bet, but if you can't get to one, get internet access somehow and you'll figure it out. GL

[Soap Mactavish]

hmm didnt know he lives in canada.   

theey may still have apple stores there in the cities.

[Hardcore]

First off, Russell no need to be rude, most people would take it too the apple store, however for w0rm i recall the case is a (apple certified retailer) and those are well, not near as connected with the common problems in Mac's as say a genius bar worker might be. And aside from that if it is a small problem there was no reason not to ask here, we aren't just pretty faces we provide good support the majority of the time.

And to the real point here: As JK said the LED test would be good to try, if you have one of the following models:

iMac G5 (20-Inch), iMac G5 (20-Inch iSight), iMac G5 (17-Inch), iMac G5 (17-Inch iSight), iMac G5 ALS (17-Inch), iMac G5 ALS (20-Inch)


You should be able to read this guide http://support.apple.com/kb/HT2831 and see if the 4 LED's come on.

What Schtick linked to is quite helpful aswell. If we know what is causing the problem based on the LED test we could give more specific answers or suggestions.

I'm betting this is likely something with ether it overheating, the fan being told that its overheating even if its not or something along those lines, i've had my computer go crazy with the fan at full speed aswell when the computer was having trouble loading the login screen, because before thats loaded the computer doesn't have any sensors running telling it what speed to go, so the computer is fail safing to high speed.