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Model A1225 / Early 2009 / 2.66, 2.93, or 3.06 GHz Core 2 Duo processor

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Computer shuts off after a few minutes of use

Hi,

My iMac (early 2009, 24") started shutting down after a few minutes of use. It's not a clean shut down. It's an instant cut-off of power.

Using Hardware Monitor, everything looks normal except with the Northbridge...

- The voltage sensor always shows 0 volts.

- The current shows 0 as well.

I've tried resetting NVRAM and SMC, but that hasn't helped.

Does anybody have any advise before I replace the system board?

Thanks,

Jay

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if you haven't already i would try cleaning the dust out, make sure the fan is still spinning, it sounds like a possible overheating issue

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Thanks Michael.

Overheating was the first thing I thought of. I tried all you suggested.

I also tried using smcFanControl to increase the fan speeds. I replaced the thermal compound on the Northbridge as it was running a little hot (about 75 degrees C at idle). It now runs about 5 - 10 degrees cooler. Everything else seems to be running cool.

So far, nothing has helped.

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Best to take the frame off and take a look at the diagnostic lights when it goes down. That will tell us where to look.

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Thanks Mayer. I did that too. It goes directly from 4 lights to 2. Unfortunately that doesn't help.

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Jay Thomas crwdns2934231:0crwdne2934231:0
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