iMac Air High CPU Usage While Idle / Kernel Issues

I am attempting to repair an MacBook Air that a customer spilled a small amount of orange juice into. I have completely taken the unit apart and thoroughly cleaned the motherboard and all components. There doesn't appear to be any physical damage done from the liquid. The problem is that the customer claims that since the spill happened the computer runs "very slow" and the CPU usage is very high even while completely idle (Bounces between 60%-80%). Being versed primarily in Windows PC Repair I am looking to post some diagnostic logs on here and maybe get some help from someone who knows what they are looking at. The customer took the machine to the Apple Store and they told them it had a "kernel problem" and would need a new Logic Board. Any help would be greatly appreciated, I just need to know what diagnostic reports I need to post to get this ball rolling... Thank you for your time.

Taylor

iRescue911 said:

The customer took the machine to the Apple Store and they told them it had a "kernel problem" and would need a new Logic Board. Any help would be greatly appreciated, I just need to know what diagnostic reports I need to post to get this ball rolling...

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I hate to say it. But if the Apple Store says that the MacBook Air needs a new logic board…then no amount of diagnostic "getting the ball rolling" is going to help. If the hardware has been damaged…it is not repairable…the logic board needs to be replaced.

Now if "getting the ball rolling" means getting the repair process rolling. Then start looking for a used logic board on e-Bay or other used parts suppliers. Once received…install the logic board…and hopefully you have a working computer.

But FYI…most times used logic boards for Apple computers are not cheap. And many times…the cost of the logic board is not worth the overall cost of the repair.

- Nick

Thank you for your prompt reply but maybe I wasn't really clear enough in my post. I realize that if the board is screwed, it's screwed. I am just wondering if there is anything (like a diagnostic report, error log, etc) that I can provide whoever is willing to help which would verify that these problems are being caused by a hardware fault on the board or if the issues are coming from something software related. For example this post over at the apple forums:
https://discussions.apple.com/message/24965987#24965987

The OP provides a bunch of diagnostic/info reports and a helpful user (Linc Davis) is able to determine his issue may be related to a few different things, not just a shot motherboard component.

As he states:
"The kernel is using excessive processor cycles. Below are some possible causes for the condition.
Throttling
When it gets high temperature readings from the hardware, or a low-voltage reading from the battery, the kernel may try to compensate by interrupting the processor(s) to slow them down and reduce power consumption. This condition can be due to
a buildup of dust on the logic board
high ambient temperature
a worn-out or faulty battery in a portable
the malfunction of a cooling fan or sensor
Note that if the problem is caused by a sensor, there may be no actual overheating or undervoltage.
If the computer is portable, test with and without the AC adapter connected. If kernel_task hogs the processor only on battery power, the fault is in the battery or the logic board. If it happens only on AC power, charging is causing the machine to heat up. That may be normal on some models. CPU usage should drop when charging is complete.
Apple Diagnostics or the Apple Hardware Test, though not very reliable, is sometimes able to detect a bad fan or sensor.
If nothing is wrong with the hardware, then whatever you can do to improve cooling may help.
Installed software
User-installed software that includes a device driver or other kernel code may thrash the kernel. That category includes virtualization software, such as Parallels and VMware, as well as most commercial "anti-virus" products. Some system-monitoring applications, such as "iStat," can also contribute to the problem. You can test for this possibility by completely disabling or removing the software according to the developer's instructions, or booting in safe mode. Note, however, that disabling a system modification without removing it or booting in safe mode may not be as easy as you think it is.
Corrupt NVRAM or SMC data
Sometimes the problem is cleared up by resetting the NVRAM or the SMC.
External display
Connecting an external LCD display to some MacBook Pro models may cause this issue. If applicable, test by disconnecting the display. You might get better results with a newer LED display." This is the type of information I am looking for.

And for the record, just because an Apple "Genius" (lol... that oxymoron always makes me giggle aloud) tells you it "Needs a new motherboard" aka "You should probably just buy a new one from us now", don't EVER just take their word for it. Those people are NOT techs. I have been professionally servicing iPhones, iPads and iPods daily for over 6 years now and have a mile long list of horror stories involving the dipshits, oops- I mean "Geniuses" that they employ at those stores... You might as well take the thing to Geek Squad.

So as I stated originally - Is there anyone here that is willing to look at the diagnostic reports/error logs and see if they can determine the exact issue and what is causing it? If I have to replace the board, I have to replace the board, no big deal. But if I do I want to understand why I am replacing the board and what exactly the cause of that issue is.

iRescue911 said:

Thank you for your prompt reply but maybe I wasn't really clear enough in my post. I realize that if the board is screwed, it's screwed.

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I agree...sometimes just because an "expert" says that a new logic board is needed...this may not always be true. I recently had a problem with an iMac...and the experts said it needed a new logic board...and it really turned out to need a new $3.00 SATA cable.

But...the fact that this situation involves a liquid spill...is a COMPLETELY different situation!!!

The link to the Apple forums (as far as I can tell) had nothing to do with a computer involved in a liquid spill.

Spilling liquids onto a energized electronic device (such as a laptop computer)...generally results in a damaged logic board via short-circuiting two or more pathways that are NOT supposed to be in contact with each other. Damaged logic boards due to a liquid spill in many cases will not show any obvious physical damage. The fact that the computer is not operating or operating properly...is proof enough that the logic board is most likely the damaged part.

- Nick

For further "fun" reading...please read this thread:

http://www.mac-forums.com/forums/ap...iquid-my-macbook-what-do-i-do-now-thread.html

The success rate of "resurrecting" a laptop that has had liquid spilled on it...is very very very low.

- Nick

I should probably state that the laptop was not doused in liquid. It really didn't even have that much inside of it. The customer merely "splashed" a bit on it and a tiny bit got in through the keyboard. While I know from my experience repairing water damaged cell phones and tablets of all types that it doesn't really matter if it was just a drop or a full on glass of liquid, especially when power is moving through the device- damage is damage. I just want to make sure that the CPU/Kernel issue is actually is being caused by the liquid damage and not something else and thought that providing someone here with diagnostic information/error logs, etc. from the machine would assure me that it is a motherboard problem directly related to the liquid damage. Am I mistaken in assuming this?

iRescue911 said:

I should probably state that the laptop was not doused in liquid. It really didn't even have that much inside of it. The customer merely "splashed" a bit on it and a tiny bit got in through the keyboard.

Click to expand...

iRescue911 said:

While I know from my experience repairing water damaged cell phones and tablets of all types that it doesn't really matter if it was just a drop or a full on glass of liquid, especially when power is moving through the device- damage is damage.

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Exactly what I was going to say after the first quote above. It really doesn't need to be doused in liquid…it can only be a couple drops/small amount…to "kill" a computer.

iRescue911 said:

I just want to make sure that the CPU/Kernel issue is actually is being caused by the liquid damage and not something else and thought that providing someone here with diagnostic information/error logs, etc. from the machine would assure me that it is a motherboard problem directly related to the liquid damage. Am I mistaken in assuming this?

Click to expand...

I totally understand what you're looking for. You want confirmation what the problem is…and don't want to give up on this computer if it's just something small (not the logic board).

Four things:

Point #1. If you've opened this MacBook Air up…you've seen how few parts there are. You got a:

- Keyboard
- trackpad
- logic board
- fan

That's just about it. You don't have a removeable hard drive, you don't have removable ram, you don't have an optical drive. So there are very few parts that can be affected by a liquid spill.

And generally…if the trackpad, keyboard, or fan is effected…they don't work properly…giving you a strong/clear indication that they are damaged. Thus…any other problem is associated with a bad logic board.

Point #2.

- If this computer is working well enough to do some diagnostic troubleshooting. With no apps open:

- launch "Activity Monitor" (Utilities Folder).
- Select "All Process's" from the drop down menu near the top of the window.
- look thru the list to see what specifically is using all of the cpu resources (other than the kernal task). If there is something else using "major" cpu resources…this may give a clue.

Point #3.

Have you tried wiping the storage on this computer…and reinstalling the OS?

Point #4.

Have you tried an SMC Reset?

- Nick

Alas all too often liquids + electronics = death.

One option may if the board has failed may be selling it as not working/parts only on eBay and such.

Plus any residual acid from the orange juice has been eating away at that circuit board for a while now. Don't you think it something of a strange coincidence that you'd get kernel panics after spilling some orange juice on a computer? I don't.

Easy way to test this -- replace the logic board, and see if the problem goes away.