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Mike, Mac Support Specialist
Category: Mac
Satisfied Customers: 2186
Experience:  Apple trained Technician, A+ Certified, 20+ years of Mac support, repairs, training, and consulting
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my mac g5 sometimes goes into overdrive on fan too the point

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my mac g5 sometimes goes into overdrive on fan too the point that i have too shut it off this also happens when it is in sleep mode or if i download a large file it has happen even when the screensaver has been on

What I would like you to do is open the Activity Monitor and see what processes are running that may be causing this.

There are a couple of them that can run away and they need to be shut down.

So, do this and then get back to me. Obviously you can't tell what's running when screen saver kicks in, but all other times fan runs on, you can go in there and look.

Go to the Go Menu in the Finder. Choose the Utilities Folder.
In here, open the Activity Monitor application.
At the bottom of the window, click on the CPU tab, and at the top click on CPU until the triangle is pointing down.

Now, look at the top 2-3 processes and see what percentage of the CPU they are using. Anything 80% or higher note down and then get back to me with the exact names and percent CPU used.

If I see anything that is known to cause a runaway, then I will get back to you with a solution to stop and hopefully prevent it in the future.

Customer: replied 8 years ago.
tanks for getting back to me mike idid what you suggested but i do not have a triangle but it i s replaced with a graph on the bottom right hand corner but from what i can see pm tool .task is reading at2.50 whatever that means also kernal task is 1.50 and2.50 it flucuates back forth window server reads 1. also i notice the window server jumping from a low of o too 1 activity monitor is at 1.90 im probobly not doing this right but i do appreaciate your help thanks
Customer: replied 8 years ago.
mike here is an update i did find the triangel sorry about that it was so small i did not notice it with all the bars an graphs on my screen activity monitior reads 2.40 pmtool 1.90and the window server is anywhere 0 too 4 they sem too go up and down normal i assume thanks
Ok, good.

So now you know where to go when the fans crank up. They should only do that when the processor is getting slammed.

When that happens, go to the Activity monitor and see what is near the top then.

Customer: replied 8 years ago.
mike you left me hanging in regards XXXXX XXXXX said i what is near the top then? please explain thanks
Oh, I thought you understood. Sorry.

I meant near the top of the Activity Monitor window. When you have the CPU column triangle pointing down, the highest usage application floats to the top.

So, for instance the fans start ramping up. You go to Activity Monitor and look at the top of the list and up there will be the highest CPU users.

Note the top 3 and their usage % and send that back to me.

Customer: replied 8 years ago.
problem with that is whenthat happens my monitor goes blang?any solutions too that thanks
Blang? Heh. that's a new technical term for me.


Just kidding.

So it goes out? If that is trued, then the problem is going to be hardware, not software causing this.

I am going to assume this is an iMac G5? Not a Mac Pro or PowerMac?

Let me know about that, because if an iMac, I would get it to a shop toot sweet and see if they can diagnose the problem.

Customer: replied 8 years ago.
mike thisisa power mac g5 when the fan goes into overdrive my screen just shuts down

It seems that when it gets overloaded, it shuts down and then goes into a safe mode until it cools off.

Then you get to turn it back on.

2 things copuld be causing this:
A software process is going crazy making the cpu work overtime and get too hot

A cpu is going bad or its thermal paste/cooling has failed and it gets way too hot during normal use.

To fix the first, I would get a Firewire drive and install a Mac OS X version on it and play with that as the boot device. If the problem never surfaces, then you know your OS is not right and maybe an Archive & install is in order.

To fix the second, I would get it to a Apple Service provider and have them run diagnostics on it to see what is wrong with the Macs heart.

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