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I have a MacBook Pro (mid 2009, 13", 2.26GH) running Mountain Lion. I started getting intermittent beach balls and lock ups and thought the hard drive was failing. I got a copy of Scannerz to test it figuring it would just fail it and I could replace the drive. Unfortunately it didn't fail the drive it looks like it's failing the system.

When I got Scannerz I did a test on it the internal drive and got about 56 irregularities and 12 errors scattered throughout the test. The manual says to retest them in cursory mode to verify the problems are repeatable. The manual says it allows 1-2 irregularities for every 10GB at the absolute max and no errors, so I'm way out of bounds since my drive is 160GB. I retest in cursory mode and all the irregularities and errors at the locations I originally found them in are gone, but now they're showing up in different locations.

I thought the test program wasn't working right so I contacted their tech support. They told me that the software detects faults and hardware faults won't correlate to the surface scan process. They told me to download this document:

I went over it but quite honestly didn't understand it. They had me make a Phoenix Boot Volume which is like another emergency volume on a USB Flash drive. They then had me unmount the internal hard drive and test it, then attach my USB backup drive to each USB port and repeat the tests. The test results are the same: sporadic errors and irregularities on every test, never repeatable.

They told me that the following are possibilities:

  1. The logic board has problems
  2. The supply has problems
  3. RAM or some other cards like WiFi that plug into the logic board may not be seated properly.

They said if it was bad blocks on the drive, the problems would be repeatable, and if it was isolated to a specific path it was probably a cable or connector problem. Unfortunately it's all over the place so I need to be thinking of problems with the actual logic board.

I rechecked and reseated the RAM, no problems. The startup system check also reports no problems.

I'm hoping this is something no more complicated than maybe a WiFi card working it's way loose. I had a problem like this a long time ago on a 15" PowerBook.

How difficult is it to open one of these things up? I opened up some of my older Macs and even though I had to be careful, it was doable. I'd like to reseat everything and try it again.

If this fails, does anyone know how to check the supply? This problem happens on both battery power and even when the power supply is plugged in. Is there anything on the supply that's fixable?

If worst comes to worst, how much does a logic board cost here in the U.S. and where can I get one at a reasonable price?


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I can see why he'd want to look at it himself. Units like those are now selling for less than an Apple visit and repair would cost.

I use Scannerz. It's the only tool on the market that can catch those types of problems...or at least the only tool on the market that's affordable :-)

In any case, I haven't worked on a model specifically like yours but I've worked on models similar. Assuming yours is similar ( has step by step instructions for your model...I just checked) the airport card isn't on the logic board, it's located in the back of the display unit under the clutch cover. You would need to check primarily for making sure that the Airport card is seated properly in the cable and connector. Unfortunately, the cable itself feeds into the logic board through the junction between the display and the base, and can be susceptible to breaking because of the constantly opening and closing of the lid. On older MacBook Pro's the Airport was on the logic board and if the screws and Kapton tape have come loose for some reason the card would tend to pop up and you could get erratic connections.

If you choose to open it up, I would do the following:

  1. Don't bother with the Airport card yet. Just check all the connectors that are immediately available, and make sure they're all seated properly. I'd then retest the unit. If errors/irregularities go away, it was probably a connection that's worked it's way partially loose creating an intermittent contact.

  2. If errors/irregularities still show up you might want to go into the display housing and disconnect Airport in them, then, with them gone try and run the tests again. If the problems disappear you've isolated the problem, but I'd bet $50 ($20,000 if I was Mitt Romney - LOL) it's a cable, not the card causing the problems.

  3. If problems still persist it's probably the logic board. There isn't really a "supply" in these things. The real supply is the battery and the charger, and on the logic board there's some minor regulation circuitry and voltage control in that but it can't be repaired to the best of my knowledge. You said the problem occurred using the battery and then using the AC adapter so I think you could rule out spikes from the AC adapter as the source of the problem.

A lot of people may think I'm insane for suggesting these procedures, but a lot of people also forget that not everyone has an Apple store near them, and some people really don't have the money to throw at a new unit.

If you open it up, be careful and gentle, and good luck.

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The easiest thing to check first is to replace the harddrive with one you know is good, or, more cheaply, test the existing harddrive in a system that you know works. If the harddrive is failing, then it will continue to fail in another computer, and the laptop will start working fine with a new drive.

I had a 2008 15" MBP that I thought had a bad logic board (computer wouldn't sleep when I wanted it to, or would sleep when I was using it). If you take it into an Apple store, I think it's $300 to have them send it off, and they fix anything that might be wrong with it. Logic board would've only set me back $50 or so from what I could find on ebay.

(I went ahead and sent it off to Apple anyways. Turns out it wasn't even the logic board that was failing, but the bluetooth module attached to the logic board; funny thing was, my bluetooth worked just fine. I'm not sure how much I would have spent replacing parts until I found the right one that was broken, but sure enough my problem was fixed when I got it back from Apple. Wasn't happy about spending $300 by any means, but I figure by the time I'd bought all the possible parts that could have been bad, sat around testing and trying them out, wondering if I'd been sent a bad part on ebay, etc., that it was close enough to justify the cost simply to hand my laptop over and have them hand it back to me in a week or so. I don't think I could have gotten parts that quickly over ebay.)

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I agree with Darth - try a known good OS. Sounds like you may have, with this Phoenix thing, but recognize that any downloaded tool may be corrupted by whatever is wrong with the system. It seems to me that Darth's decision to take it to Apple balanced time and money spent on diagnosis vs. on repair. Recently I made that same decision, and Apple really helped me out. JRTFan, you may have spent enough on research by now, and should maybe just get it fixed. – Charles Lindsay Jul 12 '13 at 16:05

Path isolation that Scannerz uses isn't really all that complicated. All they're doing is causing the CPU and drives involved to interact along specific paths and seeing if problems can be isolated to a specific path. The reason they're telling you to boot off the Phoenix boot drive, unmount the internal drive, then run tests on it is so the OS won't be attempting to access the unmounted drive. Scannerz can access it, but the OS can't and that can be used to confirm that the internal drive and its supporting circuitry and cables are OK.

The reason they use that on a drive by drive basis is because if there's a fault somewhere on the logic board, like on the USB controller chip, it's likely problems will show up on all USB drives but probably not anything else. If it's just showing up on one USB port then it's obviously port specific or related to whatever is connected to that port.

Fault detection software like Scannerz takes a little bit of thinking to make the most use of it for the more difficult problems, but it does help actually isolate problems. If you used something like Drive Genius or TechTool Pro, they would have just flagged an I/O error as a bad sector, you would have replaced your drive, and then found that you had the exact same problem.

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