Released June 2012, Model A1278. Intel processor with Turbo Boost, Up to 512 MB DDR5 Video RAM

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Error: 4SNS/1/40000000: ICOR - 21.925


When I run the Apple Hardware Test on Macbook Pro 13" 2.5 GHz 2012.

It shows me error 4SNS/1/40000000: ICOR - 21.925.

Could you explain me what wrong with my mac?

Thanks for your answer.

I understand that my logic board has problem with system sensor.

But, when I try to run AHT test again it shows me the same error but the last number is different all time.

What is this number and why is this number different each time?

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Chosen Solution

Here's a good reference: How to invoke and interpret the Apple hardware tests. I had to use my ASD lookup to get ICOR error.

So if we take your error: 4SNS/1/40000000: ICOR - 21.925 and break it down this is what we have:

4SNS System sensor

ICOR CPU 1.05 V Rail Average Current - Mac Mini (Early 2009)

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Yes, the last digit will likely be different each time you run AHT. Its the current value. really not important here. The I in the error message is current.


It's time for a new logic board


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